Correct Answer: D

Rationale: 'Paroxysm' is the correct answer as it refers to a sudden, violent seizure or outburst. The other choices are incorrect because 'revelation' means a surprising and previously unknown fact, 'nutrient' refers to a substance that provides nourishment, and 'contraption' means a machine or device that is strange or unnecessarily complicated.

Correct Answer: A

Rationale: The correct answer is A: 'stealthy.' 'Insidious' is often used to describe something that proceeds in a gradual, subtle, but harmful way. It is not directly or openly harmful like 'deadly,' nor does it mean 'collapsed' or 'new.' Therefore, 'stealthy' best captures the meaning of 'insidious.'

Correct Answer: D

Rationale: The correct answer is 'D: Capitol.' In this context, 'Capitol' is incorrect as it refers to a building where a legislative body meets. The correct term for uppercase letters is 'capital.' Choice A, 'must always,' is used correctly to emphasize the necessity of starting a sentence with a capital letter. Choice B, 'simple,' is not the incorrect word in the sentence. Choice C, 'forget,' is also used appropriately in the sentence to indicate the action of neglecting the rule.

Correct Answer: D

Rationale: The correct answer is 'D - Mr.' The salutation is the formal title used before a person's name, which in this case is 'Mr.' Other choices are incorrect as '1600 Pennsylvania Ave.' is the street address, '20003' is the zip code, and 'Ryan' is the recipient's name.

Correct Answer: B

Rationale: The correct contraction for 'They are' is 'They're.' 'Their' is a possessive pronoun indicating ownership, not a contraction. 'The're' is not a valid contraction. 'No contraction used' is incorrect as there is a contraction for 'They are,' which is 'They're.'