Which of the Following Is NOT a Reason That the President's

Which of the following is NOT a reason that the president's party is not a fully reliable presidential tool?

A) The president's party may be in the minority in Congress and thus be unable to accomplish much.
B) The more unified the president's party,the more unified the opposition party is likely to be,making for a tough fight in Congress.
C) Presidents must often appeal to the opposition party to offset defectors within the ranks of their own party.
D) Members of Congress typically prefer bipartisan legislation that enhances the public's opinion of Congress as an institution.
E) Even if the president's party holds a majority in the Senate,the filibuster makes it possible for the minority party to block the president's agenda.