The correct answer is A) to appoint committee members.
What is not the responsibility of a subcommittee is to appoint committee members.
In the United States Congress, the responsibility of a subcommittee is to consider a specific issue and then, once discussed, inform it to the full committee. Most of the time these subcommittees work and elaborate on the creation of bills. This kind of subcommittees allows legislators to gain experience in the topic at hand to make recommendations that serve the full committee.
