Suppose That in a Computer Factory, If There Is 1

Suppose that in a computer factory, if there is 1 worker, 80 computers are produced per week. If there are 2 workers, 150 computers are produced per week. If there are 3 workers, 210 computers are produced per week. Given this information and the fact that the firm receives $200 per computer, the marginal revenue product of the third worker is

A) $4,200.
B) $12,000.
C) $10,000.
D) $14,000.