What event angered Timothy McVeigh so much that he decided to bomb a government building in Oklahoma City in 1995?

Athe standoff and ensuing tragedy at the Branch Davidian compound in Waco, TX in 1993
Bthe resignation of Mikhail Gorbachev due to the collapse of the Soviet Union in 1991
Cthe election of President Clinton in 1992
Dthe declaration of war against Iraq in 1991