In the Senate, the Label "Nuclear Option" Has Been Used

In the Senate, the label "nuclear option" has been used to refer to ___ .

A) a decision to approve the president's use of nuclear weapons on a one-time basis
B) a simple majority vote to approve a long-held and important Senate rule change
C) a Supreme Court ruling that all commonly employed legislative vetoes are now unconstitutional
D) an economic recession that diminished government revenue resulting in a mandatory reduction in domestic spending