If the marginal product curve is increasing from workers 1-89 and then decreases steadily, crossing the horizontal axis at 190 workers, we know that
A) the total output curve increases from workers 1-89, decreases from workers 90-189, and becomes 0 at the 190th worker.
B) the total output curve is increasing at an increasing rate from workers 1-89, then increases at a decreasing rate until the 190th worker, after which it decreases.
C) the total output curve is increasing throughout, although at an increasing rate for the first 190 workers and at a decreasing rate after the 190th worker.
D) diminishing marginal product sets in with the 190th worker.