Rule: Phrasal Verb 'rely on'. The sentence describes the plan's foundation. A plan is based on or depends on certain assumptions. The phrasal verb 'relies on' means to depend on with full trust or confidence. This correctly describes the relationship between the plan and its underlying assumptions. Options (b) 'disputes' and (c) 'refutes' mean to argue against. Option (d) 'collapses' could be a result of relying on bad assumptions, but it doesn't describe the relationship itself.

Rule: Vocabulary of Relationships. The result is that it's 'impossible to pass any meaningful legislation', which implies a very negative and uncooperative relationship between the parties. 'Acrimony' means bitterness or ill feeling. This word accurately describes the hostile relationship preventing cooperation. Options (a) 'collaboration', (b) 'concord', and (d) 'harmony' are all positive words describing cooperation and agreement, which is the opposite of the situation.

Rule: Phrasal Verbs. The context is about starting or beginning a new, positive era. The phrasal verb 'usher in' means to mark the beginning of something new. This is the perfect fit. Options (b) 'phase out', (c) 'ward off' (avert), and (d) 'stamp out' (extinguish) are all phrasal verbs with meanings related to ending or preventing something, not beginning it.

Rule: Vocabulary of Storytelling. The presence of 'fantastical elements and exaggerated details' means the stories were made more interesting by adding things that weren't strictly true. 'Embellished' means to make (something) more attractive by the addition of decorative details or features. It is often used to describe stories that have been made more entertaining with fictional details. Options (a) 'divested' and (b) 'purged' mean to strip or remove something. Option (d) 'simplified' is the opposite of adding more details.

Rule: Vocabulary of Business Operations. The phrase 'to a country with lower labor costs' clearly indicates a move from one place to another. 'Relocate' means to move to a new place and establish one's home or business there. This is the precise term. Option (a) 'centralize' means to concentrate control under a single authority. Option (b) 'consolidate' means to combine things into a single, more effective whole. Option (d) 'expand' means to become larger, but not necessarily to move.

Rule: Vocabulary - Appearance vs. Reality. The word 'Despite' signals a contrast between her outward appearance and her inner feeling. The word needed is one for outward appearance or behavior. 'Demeanor' means outward behavior or bearing. A 'calm demeanor' contrasts perfectly with being 'extremely nervous'. Options (a) 'agitation', (b) 'trepidation' (fear), and (d) 'perturbation' (anxiety) are all words for her inner feeling of nervousness, not her outward appearance.

Rule: Vocabulary of Pollution. 'Industrial waste' is a pollutant that makes the river unsafe. 'Tainted' means contaminated or polluted. It correctly describes the negative effect of the waste on the river. Options (a) 'replete with' and (d) 'abundant in' mean filled or well-supplied with something, but they don't carry the strong negative connotation of pollution. Option (b) 'teeming with' usually refers to being full of living things (e.g., teeming with fish), which is inappropriate here.

Rule: Verbs of Praise and Punishment. 'Disruptive behavior' is a negative action that would result in punishment or scolding, not praise. 'Reprimanded' means to express sharp disapproval or criticism to (someone) because of their behavior or actions. This is the appropriate word. Options (a) 'extolled', (b) 'lauded', and (d) 'commended' are all synonyms for 'praised', which is illogical in this context.

Rule: Vocabulary of Reputation. The phrase 'he is a man of his word' indicates that his integrity is perfect and cannot be doubted. 'Unimpeachable' means not able to be doubted, questioned, or criticized; entirely trustworthy. This is the perfect adjective. Options (a) 'questionable', (b) 'dubious', and (d) 'flawed' are all negative words that mean the opposite.

Rule: Verbs of Obscuring. The context is that the mist made the peaks impossible to see, so the verb must mean 'covered' or 'hidden'. 'Shrouded' means to wrap or cover for burial, or more generally, to cover or envelop so as to conceal from view. This word is often used with mist or fog. Options (a) 'exhibited', (b) 'revealed', and (d) 'illuminated' all mean to show or make something visible, which is the opposite of the intended meaning.