That is a sentence! It has no flaws.
It connects one story to the next.
The correct answer is C. The sentence is not asking a question, so D is incorrect. B is incorrect because a quotation mark, not an apostrophe, is needed at the end of Bin's words. Finally, A is incorrect because a period is needed at the end of a sentence, not a comma.
When a quotation appears at the end of a sentence, you need both 1) a period to signal the end of the sentence, and 2) a quotation mark to signal the end of the quotation. Therefore, this sentence should read: Bin memorized the speech, but when he opened his mouth, all he could say was, "Um, I...don't remember."
1. Alice
2. He doesn’t sneak around
