One of the purposes of studying economics is to understand the a. reasons people purchase certain goods. b. reasons some resources become scarce. c. principles that explain why produces buy goods and services. d. principles that influence the production of goods and services.

The correct answer is letter D.

Studying economics brings to the student the understanding of what influences producers to actually produce certain goods and offer certain services. For example, there's something called "Factors of production" which explains the inputs put in the production of goods and services in order to make it profitable. The factors of production are: land, labor, capital and entrepreneurship.

worcester v. georgia, legal case in which the u.s. supreme court on march 3, 1832, held (5–1) that the states did not have the right to impose regulations on native american land. andrew jackson refused to enforce the ruling, the decision form the basis for most subsequent indian law in the united states.