Answer:
The answer is C. It was the same day as an earlier extremist event.
Step-by-step explanation:
The earlier extremist even was the siege at the Branch Davidian compound in the state of Waco, Texas. The law enforcement and even the US military participated in this conflict 2 years before to bring down the extremist group.
McVeigh intentionally used this date for the Oklahoma bombings to commemorate the 2nd anniversary of the siege at the Branch Davidian.
The bombings killed nearly 168 people and injured more than 600 people.