Me or my brother. Be Honest

What is the relationship between marginal external cost, marginal social cost, and marginal private cost? a. marginal social cost equals marginal private cost plus marginal external cost. b. marginal private cost plus marginal social cost equals marginal external cost. c. marginal social cost plus marginal external cost equals marginal private cost. d. marginal external cost equals marginal private cost minus marginal social cost. marginal external cost a. is expressed in dollars, so it is not an opportunity cost b. is an opportunity cost borne by someone other than the producer c. is equal to two times the marginal private cost d. is a convenient economics concept that is not real

Acrosswalk_when there are no pavement markings.

Gary lives in an area that receives high rainfall and thunderstorms throughout the year. which device would be useful to him to maintain his computer?