Branches on the Evolutionary Tree Are Sometimes Rearranged by Scientists

Branches on the evolutionary tree are sometimes rearranged by scientists because

A) new,related fossils or new information about existing fossils changes the understanding of the relationships.
B) new,unrelated fossils are intentionally put on the tree with existing fossils.
C) scientists are trying to prove a nonexistent relationship between species.
D) scientists have definitely proven a relationship between two or more species.