Answer:
d.) because the enemy could not keep its troops supplied from such a great distance
Step-by-step explanation:
In his discourse, Winston Churchill, PM of Britain amid WWII, delivers the British to guarantee them that they are protected, and that the German armed force would have it extremely hard so as to attack British, since they'd discover an ocean topped off with mines, air bombings, and the British armed force before they could even land a foot on shore and face the British armed force. They had the sea heavily guarded.