The Difference Between Short-Run and Long-Run Cost Is That in the Short

The difference between short-run and long-run cost is that in the short run,

A) there are shortages of labor that can restrict output
B) only labor can be changed to increase or decrease production
C) fixed factors of production have already been chosen
D) the market-day supply limits the amount by which producers can change production
E) all factors of production are variable