What was not true about the economy at the end of world war ii?
the gnp and corporate profits doubled.
national debt quadrupled during the war.
wage freezes reduced consumer spending.
efficiencies in farming reduced manual labor needs

C.  Wage freezes reduced consumer spending ... .. that did NOT happen.
In April, 1943, President Roosevelt put a freeze on wages and prices ... and consumer spending increased.  Spending went down in some areas of the economy, in connection with the war effort.  For instance, the percentage of consumer income spent on automobiles, as well as gas, repairs, insurance, and fees for automobiles, went down by nearly 60 percent between 1941 and 1944.  But overall consumer spending increased.  Overall household consumer spending in 1941 was $2,060. In 1944, overall household consumer spending was $2,406.  

As to answer A):The gross national product (GNP) and corporate profits did double during wartime.  There is something to be aware of with that, however.  The big increases in spending were all war-related, and much work would be needed after the war to keep the economy going forward on a peacetime footing.  David Weinberger, writing in The Daily Signal (January 26, 2012), explained:   "Underneath the national numbers that seem so robust between 1941 and 1945 stood an emaciated, barely conscious private economy stripped of resources and hope. This economy, a child of the Great Depression, bore little resemblance to its muscular cousin who fought on two war fronts."

As to answer B)  The US federal debt indeed did quadruple during World War II.  In 1941, prior to the United States' entry into the war, the national debt stood at $58 billion.  By the war's end in 1945, the national debt was $260 billion.

As to answer D):  L.D. Baver, the Associate Director of the North Carolina  Agricultural Experiment Station from 1941 to 1947, explained the emphasis being given through agricultural extension programs:  "The job of farming in war time, like the job of war itself, consists in making the most effective use of all available means -- labor, machinery, fertilizer, facts"  (Research and Farming, N.C. Agricultural Experiment Station annual report, 1942).