The error in this sentence is a A) pronoun-antecedent voice agreement error. But it should be noted that this has become more standard usage in common dialogue.
Explanation:
this app helps you to ask questions about something you don't know or answer other people's questions.
I was just getting Takis before watching The Walking Dead.
This cartoon dipicted the Sherman-Act of 1890, so the correct answer for his question is B.
