Answer: A. "Go now with Mr. Walsh."
Explanation:
The imperative mood is when a statement or someone demands an action to be performed. So all the other choices:
B "Can you go with Mr. Walsh?"
Option B is a question, not a command. And, apparently, it seems asked as a favor.
C "Have you gone with Mr. Walsh?"
Option C here is just a fundamental question. It has nothing to do with telling someone to do something. Instead, it asks if someone has done something.
D "You might want to go with Mr. Walsh."
Option D appears to give a suggestion. The word "might" seems like something that would encourage the listener to do something. Moreover, it is not a command.
For Option A, the correct option, we see the speaker is telling someone to do something, more precisely, go somewhere. Given that information, we can infer that the speaker commands the listener to go somewhere, defining an imperative mood.
