All Else Equal, Forecasting Your Firm's Demand Is Likely to Be

All else equal, forecasting your firm's demand is likely to be less profitable if any of the following are true except for which one?

A) A change in your output level leads to a large change in the firm's marginal cost.
B) A change in your output level leads to a small change in the firm's marginal cost.
C) Your firm experiences small fluctuations in demand.
D) It is difficult to obtain an accurate forecast of your firm's demand.