Final answer:
The correct answer is option C) By imposing trade restrictions and impressing American sailors.
Step-by-step explanation:
The British continued to be a problem for the United States during Washington's presidency by imposing trade restrictions and impressing American sailors, option C.
Britain blockaded Europe during the conflict between France and Britain. This blockade affected American trade and led to tensions between the United States and Britain. Additionally, the British navy captured American ships on the high seas and impressed their sailors into service for the British, which further strained relations between the two countries.
Overall, the British actions of imposing trade restrictions and impressing American sailors created significant problems for the United States during Washington's presidency.