**Rule:** 'Will' is used to express a strong belief or prediction about the future, often based on opinion. The phrase 'I am confident' indicates such a belief. While 'is going to win' (option c) is also possible if there's evidence, 'will' is the classic choice for expressing personal confidence. Options (a) and (b) are incorrect.

**Rule:** The Future Perfect Tense (will have + past participle) is used to mark the completion of a duration ('for 20 years') by a specific future point ('This time next week'). It focuses on the milestone of the 20-year duration being completed. Option (a) simply states their marital status at that future time.

**Rule:** The Future Perfect Continuous Tense (will have been + verb-ing) is used to emphasize the duration ('for a decade') of an action up to a specific point in the future ('by the time he leaves next year'). This tense perfectly captures the length of his employment up to his departure.

**Rule:** The passive voice structure 'is expected to' is commonly used for formal predictions and projections based on data or expert opinion. The population is the receiver of the expectation. Option (b) is active voice and incorrect because the population itself does not expect. Option (c) is future perfect continuous. Option (d) is grammatically awkward.

**Rule:** The Future Perfect Continuous Tense (will have been + verb-ing) is used to emphasize the duration ('for seven years') of a continuous state or action up to a specific point in the future ('By the time he graduates').

**Rule:** The Future Perfect Tense (will have + past participle) is used to express that an action will be completed by a specific future deadline. 'By next Friday' is the deadline by which the action of grading will be finished. Option (d) implies the work will be in progress on Friday, not necessarily finished.

**Rule:** The negative form of the Future Perfect Tense (will not have + past participle) is used to state that an action will not be completed by a specific future time. The speaker predicts the renovation will still be incomplete at the future point 'by the time we move in'. Option (d) is also possible but (b) better emphasizes the state of incompletion at a deadline.

**Rule:** The Simple Future with 'will' is used here to make a promise or state an intention that is conditional on another event. The time clause 'as soon as I finish mine' uses the simple present, and the main clause correctly uses 'will help' to describe the resulting action. Option (d) is possible but 'will' is very common in this structure.

**Rule:** In future time clauses introduced by conjunctions like 'as soon as', 'when', 'before', 'after', or 'unless', the Simple Present Tense is used to refer to a future event. The main clause uses a future tense ('we will be able to leave'). Option (a) 'will arrive' is incorrect because 'will' is not used in the future time clause. Option (c) 'is arriving' could be possible for a fixed arrangement, but simple present is standard. Option (d) 'will have arrived' is grammatically incorrect in this structure.

**Rule:** 'Be going to' can be used for predictions based on a present feeling or intuition. 'I have a feeling' is the present evidence, making 'is going to happen' a natural choice to express the prediction. 'Will happen' would also be possible but 'going to' connects more strongly to the present feeling.