The United States-Korea Trade Agreement, a Trade Agreement Signed by U.S.President

The United States-Korea Trade Agreement, a trade agreement signed by U.S.President George W.Bush and South Korean President Roh Moo-hyun in 2007, won congressional approval in 2011 after being given an okay by majorities in the House and Senate.This made it a classic example of:

A) a multilateral agreement-that is, a treaty between more than two countries.
B) the House encroaching on the Senate's power by demanding a say in treaty approval.
C) a bilateral treaty-that is, treaties between two countries.
D) 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 just the Senate.