The last time the U.S. Post Office raised its prices for mail service

The last time the U.S. Post Office raised its prices for mail service critics of the rate increase argued that the Post Office’s revenues would actually decline as a result of the price increase. It can be concluded that:

A) both groups believe demand is elastic, but for different reasons.
B) both groups believe demand is inelastic, but for different reasons.
C) the Post Office believes demand for mail service is elastic; opponents of the price increase believe demand is inelastic.
D) the Post Office believes demand for mail service is inelastic; opponents of the price increase believe demand is elastic.

ANSWER

D