Which scenario is an example of how the separation of powers affects the US government?
(a) The president vetoes a popular law that has been passed by Congress.
(b) Congress calls a hearing to ask the head of the EPA to explain the impacts of a new regulation.
(c) The Supreme Court rules on a controversial case to outlaw a common practice in many states.
(d) During a hearing, a senator argues against approving the presidential nominee for secretary of state.