Rule: Logical Inference. For ruins to be 'revealed', the thing covering them must have been removed or pulled back. 'Receding' means to go or move back or further away from a previous position. The receding of the rainforest (due to deforestation or climate change) would logically reveal what was underneath. Option (a) 'canopy' is a part of the forest. Options (c) 'growth' and (d) 'expansion' would hide the ruins, not reveal them.

Rule: Legal/Formal Vocabulary. The detailed conditions or requirements of a formal agreement are called stipulations. 'Stipulations' are conditions or requirements that are specified or demanded as part of an agreement. The fact they were 'complex and required careful study' points to this formal term. Options (a) 'summaries', (b) 'outlines', and (d) 'generalities' all refer to less detailed aspects of the agreement.

Rule: Vocabulary of Personality. A child who is 'always asking questions and exploring' is curious and eager for knowledge. 'Inquisitive' means having or showing an interest in learning things; curious. This word perfectly describes the child. Options (a) 'apathetic', (b) 'lethargic', and (d) 'indifferent' are all words for a lack of interest or energy.

Rule: Vocabulary of Literature. A book that is a collection of writings (in this case, essays) is often called a compendium. 'Compendium' is a collection of concise but detailed information about a particular subject. It fits the description of a collection of essays. Options (b) 'novel', (c) 'poem', and (d) 'play' are different literary forms and are not collections of essays.

Rule: Vocabulary of Amount. A 'growing problem' concerning a vital resource like fresh water would be a lack of it. 'Scarcity' means the state of being scarce or in short supply; shortage. This word accurately describes the problem. Options (a) 'abundance', (b) 'surplus', and (d) 'plethora' (an excess) are all antonyms, meaning there is more than enough.

Rule: Vocabulary of Lifestyles. If doctors advise 'exercise and a healthier diet', the patient's current lifestyle must be inactive. 'Sedentary' means (of a way of life) characterized by much sitting and little physical exercise. This is the correct term. Options (a) 'active', (b) 'energetic', and (d) 'vigorous' are all antonyms and describe the lifestyle the doctors were recommending.

Rule: Vocabulary of Health. A 'secondary infection' is a negative development that would make a patient's condition worse. 'Deteriorate' means to become progressively worse. This is the correct medical term for the patient's decline. Options (a) 'improve', (b) 'ameliorate' (make better), and (d) 'recover' are all antonyms.

Rule: Literary/Rhetorical Devices. A situation where the outcome is the opposite of what was intended is known as irony. 'Irony' is a state of affairs or an event that seems deliberately contrary to what one expects and is often amusing as a result. The policy hurting those it was meant to help is a perfect example of situational irony. Options (a) 'beauty', (b) 'benefit', and (d) 'success' are all contradicted by the outcome.

Rule: Vocabulary of Conflict. A prolonged, bitter quarrel between families or groups is called a feud. 'Feud' is a state of prolonged and bitter hostility between two families or other groups. This is the precise term for the situation described. Options (a) 'truce', (c) 'accord', and (d) 'pact' are all words for agreements or cessations of hostility.

Rule: Vocabulary of Believability. A story 'full of contradictions and inconsistencies' is not believable or reasonable. 'Plausible' means (of an argument or statement) seeming reasonable or probable. The sentence states the story was NOT plausible. Options (b) 'credible', (c) 'consistent', and (d) 'coherent' are all similar in meaning and also fit, but plausible is a very common word in this context, contrasting an unbelievable story with a believable one.