If You Are a Wheat Farmer and You Want to Earn

If you are a wheat farmer and you want to earn as much profit as you can, you should do which of the following:

A) try to produce and sell that quantity of output at which marginal cost has risen to equality with price.
B) try to produce and sell that quantity of output at which marginal cost is equal to average variable cost.
C) try to produce and sell that quantity of output at which marginal cost has reached its minimum possible level.
D) never let marginal cost reach equality with price, since this is the point at which profits become zero.
E) keep marginal cost above price.