The greater the magnitude of the external benefits of production, a. The larger is the deadweight loss from underproduction. b. The greater would be the optimal tax. c. The less the private market solution would deviate from the socially efficient level of output. d. All of the above are true.

d. All of the above are true

Explanation:

External costs happen if during production or consumption of a good or a service there is a negative effect on another party. The existence of this can bring about market failure. In the presence of externalities social benefit costs are a combination of private costs and also external benefits of production.

All of the options a, n and c are true so d is the answer here.

the assumption the narrator makes in this excerpt is that the messages he heards were going to hurt the narrator's mom; the narrator just springs in to action. the narrator doesn't specify in this excerpt why he believes that the messages present a problem that requires protection.