听力原文： In the US, Democratic presidential candidate (9) Barack Obama has dismissed a suggestion by rival Hillary Clinton that he run as vice presidential candidate on her ticket. Obama says he has won twice as many states as Clinton. He also says he has won more popular votes and has more delegates than Clinton. And that it's obvious that he will NOT become the running mate of a candidate in second place. Clinton and her husband—former President Bill Clinton—have been putting forward the idea of a joint ticket in recent days. But supporters of Obama say Clinton's proposal is only a political maneuver. Clinton is locked in a tight battle with Obama to win the race to become the Democratic nominee to face Republican Senator John McCain in the November election.
What was Baraek Obama's response toward HillARy's suggestion?
A．He made no eomments on Hillary's suggestion.
B．He had no choice but to accept Hillary's suggestion.
C．He refused to take Hillary's suggestion.
D．He decided to quit the election campaign.