If increases in capital per worker lead to increased output per worker, but by decreasing amounts as capital increases, the per-worker production function _____

Which of the following provide the best evidence of specialization?

a. a firm that produces a line of related products, such as eight kinds of breakfast cereal b. an architect who is willing to practice in only one geographic area c. a physician that practices in a specialty area such as cardiology or orthopedic surgery d. a family that eats at Wendy's every Thursday night e. a retailer that sells goods but provides no services

For a person earning $75,000, the marginal tax rate for the amount from 10,001 to $15,000 is:

A. 10%
B. 15%
C. 25%
D. 27.5%