Who was the president of US, At the time of invasion of Afghanistan after 9/11 attacks?

A. Bill Clinton
B. George W. Bush
C. Barrack Obama
D. None of these

Explanation:

President George W. Bush signs into law a joint resolution authorizing the use of force against those responsible for attacking the United States on 9/11. This joint resolution will later be cited by the Bush administration as legal rationale for its decision to take sweeping measures to combat terrorism, from invading Afghanistan to eavesdropping on U.S. citizens without a court order, to standing up the detention camp at Guantanamo Bay, Cuba.