Despite the Postal Service's Legal Monopoly Over First-Class Mail Delivery

Despite the Postal Service's legal monopoly over first-class mail delivery,

A) the price of a first-class stamp has not changed for over a decade
B) the price of a first-class stamp has fallen as delivery volume increased
C) it still produces along the inelastic range of the market demand curve
D) its faces competition from foreign suppliers
E) it has lost huge chunks of other mail classes to private firms