Given a text T, and several options, according to the question posed in the text T to choose the most appropriate option from the options as the answer, please directly output the most appropriate option, do not need to output the explanation.

When graphically depicting the life-cycle model for an industry as a curve, the variables on the axes are:
Option A:price and time.
Option B:demand and time.
Option C:demand and stage of the life cycle.

Answer: B