Congress passes legislation that requires all people to have health insurance or pay fines to the government. The president analyzes the legislation and signs it. Several different individuals challenge the law as unconstitutional and the United States Supreme Court agrees to hear the case. After the hearing, the justices declare that the law is constitutional. This is an example of: a. the supremacy clause. b. the federal form of government. c. the system of checks and balances. d. preemption.