For a common resource, the marginal private benefit of the resource is greater than the marginal social benefit

Liam wants to buy some milk and a box of cereal. If Liam buys 4 gallons of milk at $3.00 per gallon, the box of cereal costs $2.00 . If he buys 5 gallons of milk, the box of cereal is free. For Liam, the marginal cost of buying a fifth gallon of milk is

a. zero. b. $1.00. c. $2.00. d. $3.00.

Joe and Pam are neighbors. Joe asks Pam to drive him to the airport. Before leaving, Joe pays for Pam to fill her car's gas tank at the local gas station. Joe's trip to the airport would be ________.

A. not counted in GDP because the trip does not involve any formal market transactions B. counted in GDP because Joe purchased the gas C. not counted because nothing was actually produced D. counted in GDP because Joe and Pam represent different households