Which Approach Did Congress Use in 1973 to Compel States

Which approach did Congress use in 1973 to compel states to adopt a maximum speed limit of 55 miles per hour?

A) It threatened to increase gas taxes on all states that did not adopt the new speed limit.
B) It passed legislation to withhold federal highway funds from states that did not adopt the new speed limit.
C) It filed lawsuits in federal court suing all states that did not adopt the new speed limit for violations of the Environmental Protection Act.
D) It enacted a law that provided massive cash grants and tax cuts for every state that adopted the new speed limit.