The answer is C. Cepillen.
I just got it right on my flvs test.
Explanation: Since you're commanding multiple people the correct answer is abran.
Thie way my Spanish teacher taught me how to change a word to the uds form for a command:
First, put the word in the yo form - abro
Second, take away the o - abr
third, put the opposite ending the word would normally get in that form ( if get would normally get an e in that then give it an a and vice versa) - Abra
Fouth, give it an n (bc words in the uds form get end in n) - Abran
And that your answer.
I think it is beban
Beban is commanding "the others" to drink