Kennedy Was Often Cautious and Frustrated in Advancing Social Reform

Kennedy was often cautious and frustrated in advancing social reform and civil rights legislation because

A) he was looking forward to winning a much larger mandate in the election of 1964.
B) the civil rights movement's militant demands undercut public support for moderate reform.
C) his own vice president, Lyndon Johnson, lobbied against the legislation behind his back.
D) conservative southern Democrats controlled key Congressional committees.
E) Republican majorities in the Senate blocked his legislative proposals.