The marginal benefit to Bob of a taxi ride to work today is $5. The price of a such a ride is $4 and is equal to the marginal cost of the ride to Bob. Assuming Bob is rational, it follows that:

a. There is not enough information to determine whether or not Bob will choose to ride to work in a taxi today.
b. Bob will enjoy a net gain by riding to work in a taxi today.
c. Bob will not choose to ride in a taxi today.
d. Bob will choose to ride to work in a taxi today.
e. Both (b) and (d)