(A) Donald Trump
(B) ** John McCain
(C) Michael Warm
(D) Joe Biden
EXPLANATIONS BELOW
Concept note-1: -On November 4, 2008, Obama defeated the Republican nominee, Senator John McCain of Arizona, making him the President-elect and the first African American elected President.
Concept note-2: -On February 10, 2007, Barack Obama, then-junior United States senator from Illinois, announced his candidacy for the presidency of the United States in Springfield, Illinois. Obama announced his candidacy at the Old State Capitol building, where Abraham Lincoln had delivered his “House Divided” speech.
Concept note-3: -However, due to a close race between Obama and Senator Hillary Clinton of New York, the contest remained competitive for longer than expected; neither candidate received enough pledged delegates from state primaries and caucuses to achieve a majority, without endorsements from unpledged delegates (superdelegates).