If 400 Apple Pies Are Sold at $4 Per Pie

Multiple Choice

If 400 apple pies are sold at $4 per pie, but 600 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.