The united states congress may pass laws, and they go into effect if the president signs the law. however the supreme court can declare a law unconstitutional. this is an example of

Checks and balance

Explanation:

Checks and balances is referred to as a system in the federal government that was developed and implemented in order to make sure no branch of government tends to become too much powerful. The individuals that gave the U.S. Constitution, also divided to a system that tends to divide the power in between three branches of United States government, i.e. executive, legislative and judicial.

can you explain a little further maybe give multiple choice? ?