The New START (Strategic Arms Reduction Treaty), a Replacement for an Older

The New START (Strategic Arms Reduction Treaty) , a replacement for an older nuclear arms reduction treaty between the United States and the Russian Federation that was signed by President Obama and then-Russian President Dmitry Medvedev and ratified by the Senate in 2011 after a 71-26 vote in its favor, was a classic example of:

A) an executive-congressional agreement, which must be approved by a majority vote of the House and Senate, rather than a two-thirds "supermajority" vote in only the Senate.
B) a multilateral agreement-that is, a treaty between more than two countries.
C) a bilateral treaty-that is, treaties between two countries.
D) the Senate exercising more power in foreign affairs than the president.