The president pro tempore of the Senate:

A. is the longest-serving member from the majority party.
B. also serves as the chamber’s majority leader.
C. is the most powerful party leader.
D. appoints members of the Rules Committee.

B?

Nope.

well, then A?

Yes, A. It is not required in the Constitution (it could be any Senator), but it has been custom to choose the most senior member of the majority party since the 1890s, and always since 1949.

thank you! very appreciate your help

You're welcome.

Who was the leader of the War Party?

The correct answer is A. The president pro tempore of the Senate is the senator who presides over the Senate in the absence of the Vice President, who is the President of the Senate. The president pro tempore is typically the longest-serving member of the majority party in the Senate. This position does not serve as the chamber's majority leader (answer B), nor is it the most powerful party leader (answer C). Additionally, the Rules Committee is not appointed by the president pro tempore, so answer D is also incorrect.