HELP PLEASE A jewelry store sells charm sets that each contain three heart charms and c character charms. After buying several of these sets as gifts from the store, Mrs. Thompson had a total of 20 charms.

Which expression represents the number of charm sets Mrs. Thompson bought?

A. 20 / (3 + c)

B. 20 x 3 + c

C. 20 / 3 + c

D. 20 x (3 + c)