​What Precipitated Congress's Efforts to Lower the Voting Age from Twenty-One

​What precipitated Congress's efforts to lower the voting age from twenty-one to eighteen?

A) ​Civil rights protests regarding voter registration in the South
B) ​Student protests regarding Vietnam and the mandatory draft
C) ​The failure to ratify the Equal Rights Amendment
D) ​The Bay of Pigs incident and the escalation of the Cold War