The headline of a story is not the authors name. So the correct answer is (FALSE)
The squad wanted to choose their own captain.
Let's take an example. An adverb is basically an adjective for a verb: it describes a verb, and often ends in -ly. Here's a sentence, WITHOUT PROPER PUNCTUATION: "Slowly Anna walked." What fits here?
Let's work backwards. If D is correct: "Slowly. Anna walked." This is incorrect, because this would make "slowly" part of a separate sentence, not the beginning of the same sentence. This is the same situation for C. If it were correct: "Slowly! Anna walked." This makes it a separate sentence, so C is incorrect. What about B? "Slowly; Anna walked." This is incorrect because it makes "slowly" too separate from "Anna walked." Semicolons are used for completely separate ideas, NOT adverbs. The only right answer is A: "Slowly, Anna walked." This separates the adverb enough so it doesn't confuse, but you still know we are really saying "Anna walked slowly."
Answer: A: a comma
