The Supreme Court's Decision in Citizens United V

The Supreme Court's decision in Citizens United v. Federal Election Commission (2010) was significant because it concluded that the

A) Constitution prohibits the government from limiting campaign spending in any way.
B) Constitution allows the government to prevent certain candidates from running campaign ads.
C) Constitution allows the government to ban political speech funded by corporations.
D) Constitution prohibits the government from regulating political speech funded by corporations.
E) "millionaire's amendment" to the Bipartisan Campaign Reform Act was consistent with the Constitution.