One principle of the constitution is the rule of law. Which of the following is an example of the rule of law?

A - The President is exempted from paying taxes that others must pay.

B - The Secretary of Agriculture is punished for stealing money from the government treasury.

C - A worker in the Department of Labor is not required to testify as a witness in a court trial.

D - A member of congress is not requires to pay the fine for a parking ticket.