The WPB or War Production Board set the products that would be needed for war and they determined their pricing.
So I agree with you, the answer is A.
But I must admit I was a bit iffy between A and D but I'd still say that A is a better choice.
Hope this helped
Answer:
"this paper looks to me as if it knew what a vicious influence it had"
It was important because it the case gave the Supreme Court the power of judicial review, the Supreme Court to limit the of congressional power, and it challenged a law that was passed by Congress and signed by the president