The problem is that the Congress is bicameral, and neither of the chambers is known as more important - so the leader of either of the chambers would be an option. However, the Senate is usually seen as a little more important - so the leader of the senate, which is the Vice President (d)
The trail of tears was a part of the removal of native cherokee indians from their territories east of the mississippi to western territiories such as oklahoma.