Economics is different from other social sciences because it gives special emphasis to the study of ; it is similar to other social sciences because they are all concerned with the study of .

The correct answer is letter "C": opportunity costs; choices.

Explanation:

The main focus of Economics is the study of scarcity. Scarcity pushes individuals to make trade-offs because their needs are unlimited but the resources to fulfill those needs are finite. Then, individuals must analyze the opportunity costs of choosing one product or service or another to satisfy their wants.

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.

the answer would be voluntary exchange -

"the act of buyers and sellers freely and willingly engaging in market transactions. moreover, transactions are made in such a way that both the buyer and the seller are better off after the exchange than before it occurred."

hope this : )

-shy