The "Switch in Time That Saved Nine" Referred to A(n)

The "switch in time that saved nine" referred to a(n)

A) filibuster in the early nineteenth century that limited the number of federal district courts to nine.
B) attempt by the Republican-dominated Senate in 1994 to confirm as many conservative judges as possible before the midterm elections.
C) Supreme Court justice who had been voting to strike down New Deal policies changing his vote to support the policies in response to a plan by President Roosevelt to increase the size of the Supreme Court.
D) series of early twentieth-century Supreme Court decisions that reaffirmed the importance of the Ninth Amendment.