When the president appoints someone to (say) the Supreme Court, he knows congress is going to raise a protest. That is a limitation on his power. He cannot appoint just anyone. There will be opposition. Not A
Impeachment. How much bigger a limitation can there be? Removal from office is certainly a limitation of power. Not B
Overriding a veto. The president says no. Congress says yes. Congress eventually wins. Not C.
D is a power granted to the executive branch. It is the answer.