Which fact is the BEST piece of supporting evidence that overproduction and falling prices was a cause of the Great Depression?

Question

Which fact is the BEST piece of supporting evidence that overproduction and falling prices was a cause of the Great Depression?

Responses
A In 1930 over 1,350 banks closed and customers lost all their savings.In 1930 over 1,350 banks closed and customers lost all their savings.
B The unemployment rate in 1929 was 3.2% and by 1933 there was a 25% unemployment rate.The unemployment rate in 1929 was 3.2% and by 1933 there was a 25% unemployment rate.
C In 1920 a bushel of wheat sold for $2.94, in 1929 it sold for $1.00 and by 1932 a bushel sold for .30 cents.In 1920 a bushel of wheat sold for $2.94, in 1929 it sold for $1.00 and by 1932 a bushel sold for .30 cents.
D The stock market's Dow average dropped over 23% over a two-day period in October of 1929 and lost 90% of its value by 1932.

Answer 1

C In 1920 a bushel of wheat sold for $2.94, in 1929 it sold for $1.00 and by 1932 a bushel sold for .30 cents. This fact directly demonstrates the impact of overproduction causing falling prices, leading to economic turmoil during the Great Depression.