Question

The use of submarines during World War I had which of these effects? It gave an advantage to the coastal nations.

It made naval battles the key battles of the war.
It made it difficult for merchants to bring supplies to the Allies.
It prevented the Central Powers from transporting troops.

Answer 1

Answer: C.

It made it difficult for merchants to bring supplies to the Allies.

Step-by-step explanation:

Answer 2

It made it difficult for merchants to bring supplies to the Allies.