63. After July, anyone disposing of or servicing refrigerators must capture the chlorofluorocarbons in the refrigerant chemicals.
(A) anyone disposing of or servicing
(B) those who dispose or service
(C) anyone disposing of or who services
(D) the disposal or repair of
(E) someone who disposes or repairs

OA is A

I understand there is nothing wrong with the OA,. I selected B. Can someone explain why B is wrong?