Market failure is most likely to exist when:?

[Vinny]

A) marginal private benefit is equal to the marginal social benefit from a
consumption activity.
B) property rights exist.
C) there are many competitors in the market.
D) marginal social costs exceed marginal private costs from a production activity.

[Irenewy]

D）MSC>MPC lead to negative externalities, a main cause of MF

[Aleconomixt]

D) marginal social costs exceed marginal private costs from a production activity.

[Lucky]

D) marginal social costs exceed marginal private costs from a production activity.