If the Marginal Benefit of a Good Exceeds Its Marginal

If the marginal benefit of a good exceeds its marginal cost,

A) we should produce less to achieve the allocatively efficient use of resources.
B) we should produce more to achieve the allocatively efficient use of resources.
C) we've achieved efficient resource use.
D) we cannot tell if more or less should be produced to achieve the allocatively efficient use of resources.