Which of the following is most likely sold in a monopolistically competitive market?

What are the three motives for holding money?

A) the medium of exchange motive, the store of value motive, and the unit of account motive B) the transaction motive, the speculative motive, and the liquidity motive C) the transaction motive, the investment motive, and the liquidity motive D) the transaction motive, the speculative motive, and the precautionary motive

The optimal level of pollution occurs where the marginal social benefit is equal to

a. marginal private cost, which equals marginal social cost plus marginal external cost b. marginal social cost, which equals marginal private cost plus marginal external cost c. marginal external cost, which equals marginal private cost plus marginal social cost d. marginal private cost, which equals marginal social cost plus marginal internal cost e. marginal social cost, which equals marginal private cost plus marginal internal cost