Why did the supreme court deem two policies of the first new deal unconstitutional?

The National Recovery Administration was deemed unconstitutional as the court stated the combination of labor, industries, and the government was an overstep of the federal government's power. In particular it gave too much power to the executive branch as FDR's cabinet was responsible for meeting with labor and industry representatives. 
The Agricultural Adjustment Act was also deemed unconstitutional for the same reason as the NRA--the government was too involved in economic affairs. The AAA was to correct the overproduction and surplus of the farming industry by buying livestock and grain surplus off of farmers. This would allow farmers to pay debts and to drive up prices of farm products. However, court stated the government could not be a consumer in the economy. 

The correct answer is b