I think it’s D but I need to make sure
C. concerned.
I think Benvolio is concerned because when hes speaking to Montague he says he had seen how depressed Romeo was but he didn't want to go after him because he wanted to be alone but he reassured Montague that he would go and check on romeo if he was OK....<span />
So that if something is not correct they doblethink to make sure and find the solution.