Under What Circumstances Would It Be Efficient to Charge a Positive

Multiple Choice

Under what circumstances would it be efficient to charge a positive price for drivers to cross the Champlain Bridge in Montreal or the Lion's Gate Bridge in Vancouver?

A) when it is possible to exclude drivers from the bridge
B) when it is not possible to exclude drivers from the bridge
C) when the sum of marginal benefits to all drivers is positive
D) when the marginal private benefit to the last driver is greater than the marginal private cost to that driver
E) when congestion on the bridge means that the marginal cost of providing access to one more driver is positive