The word "grouse" in this context typically means to complain or grumble. So, the correct option is: complain; grumble. The correct option is A.
The most accurate paraphrase of W.E.B. Du Bois's meaning in lines 31-32 would be: Your quiet approach is a good one. I will take your advice. The correct option is C.
The word "grouse" is used in a specific context, and its meaning is derived from that context. In this case, the most appropriate meaning of "grouse" at the end of line 22 is to complain or grumble.
This paraphrase retains the idea of suggesting that the person's approach (likely quiet or non-confrontational) is considered a good strategy, and the speaker is willing to follow that advice. It conveys a positive response to the other person's approach while also expressing a commitment to continue the fight.
The correct options are A and C.