For a Factor Price Taker, the Marginal Factor Cost Curve

For a factor price taker, the marginal factor cost curve

A) and the factor supply curve both slope upward, but are not identical.
B) and the factor supply curve are identical and horizontal.
C) is horizontal, but the factor supply curve slopes upward.
D) slopes upward, but the factor supply curve is horizontal.
E) and the factor supply curve are identical and slope upward.