If 400 Apple Pies Are Sold at $4 Per Pie

Multiple Choice

If 400 apple pies are sold at $4 per pie, but 500 apple pies are sold at $3 per pie, we know from the total revenue rule:

A) ​that the demand for pies is elastic over that price range.
B) ​that the demand for pies is inelastic over that price range.
C) ​that the demand for pies is unit elastic over that price range.
D) ​nothing about the elasticity of demand.