How Has the Seniority System Been Altered When Choosing Chairs

How has the seniority system been altered when choosing chairs of congressional committees?

A) The most senior member is no longer automatically made the chair.
B) Chairs now automatically assume their position by being the longest-serving party member.
C) The oldest member of each committee now becomes the chair.
D) Chairs are no longer appointed by the leader of the majority party.
E) Chairs are appointed by the president and confirmed by the Senate.