The Formula for the Arc Price Elasticity Can Be Written $\Delta$

Multiple Choice

The formula for the arc price elasticity can be written (where $\Delta$ Q denotes the change in Q) as:

A) $\eta$ = [ $\Delta$ Q /(Q₁ + Q₂) ]/[ $\Delta$ P/(P₁ + P₂) ].
B) $\eta$ = [ $\Delta$ Q /(Q₁ + Q₂) ]/[ $\Delta$ P/(Q₁ + Q₂) ].
C) $\eta$ = [ $\Delta$ Q /(P₁ + P₂) ]/[ $\Delta$ P/(Q₁ + Q₂) ].
D) $\eta$ = [ $\Delta$ P /(P₁ + P₂) ]/[ $\Delta$ Q/(Q₁ + Q₂) ].
E) none of the above.