Answer:
.
Explanation:
If youre asking how it helped soldiers in ww2: It could have spread to the enemy spreading disease amongst enemy soldiers, most likely killing them after a while.
But if youre asking how it helped cause the war: It could have helped cause the war by all the unrest in the world at the time or people could have immigrated to enemy countries and spread the virus.
4. All of the Above. A good summary should have details.
The answer is not A, because it is not clear enough. Who's we?
The answer is not B, the sentence is not clear about the building they are visiting.
The answer is not C, it's not clear about what building they are talking about.
So your answer is D.