If E Were the Old Equilibrium in the Market for Wheat

Multiple Choice

If E were the old equilibrium in the market for wheat in the figure below, and E' the new one, which of the following could have caused the change?

A) Consumer income rose, causing a supply shift.
B) Bad weather caused a supply shift.
C) Consumer income rose, causing a demand shift.
D) Supply and demand both shifted.
E) None of the above are plausible descriptions.