Answer:
Option B, or "excuse me?" best shows Marcus is confused.
Explanation:
The definition of confused is feeling an inability to understand, or in a disordered state.
If Marcus were to be confused, it's likely that he'd ask a question to fully understand the concept. Option B ends with a question mark, which means he's trying to ask a question (excuse me?) because he is confused. This means someone would repeat what they just said so Marcus would further understand the concept. Therefore, Option B makes best sense in the given sentence.
Pls brainliest answer! :)