Which of the following statements is true? Group of answer choices

In the market for resources, firms use resources to produce goods and services and try to earn profits by selling them.

In the market for products, households supply their labor, capital, land and entrepreneurship ability to firms, and earn income from them.

A key assumption in the economic models studied in the course is as follows: Households own all resources in the economy.

All of the above.

Only a) and b)