Correct Answer: C

Rationale: The comma after 'home' is unnecessary and should be removed. In this sentence, 'and' is joining two independent clauses, which doesn't require a comma before it. Choices A, B, and D are incorrect because they are correctly placed commas within the sentence.

Correct Answer: A

Rationale: The correct answer is A - 'Went to the store yesterday.' This sentence is a fragment because it lacks a subject. A complete sentence should have both a subject and a verb. Choice B, C, and D are all complete sentences as they have both a subject ('She') and a verb ('went'). Therefore, they are not fragments.

Correct Answer: D

Rationale: The correct answer is 'Not enough.' The prefix 'hypo-' means 'under' or 'not enough,' as seen in the word 'hypokalemia,' which refers to low levels of potassium. 'Better' (choice A), 'Above' (choice B), and 'Too much' (choice C) are all incorrect because they do not convey the meaning of insufficient or low levels associated with hypokalemia.

Correct Answer: B

Rationale: The correct answer is "But". A conjunction is a word that connects words, phrases, or clauses. In this case, "But" is a conjunction used to indicate a contrast or opposition between ideas. The other choices, "Quickly", "Very", and "Apple", are not conjunctions. "Quickly" is an adverb, "Very" is an adverb, and "Apple" is a noun, none of which serve the function of connecting words, phrases, or clauses as conjunctions do.

Correct Answer: C

Rationale: The comma after 'home' is unnecessary and should be removed. In this sentence, 'and' is joining two independent clauses, which doesn't require a comma before it. Choices A, B, and D are incorrect because they are correctly placed commas within the sentence.