The Marginal Factor Cost Curve for a Monopsonist Is

The marginal factor cost curve for a monopsonist is:

A) upward sloping, unlike the horizontal curve for a firm buying factors of production in a perfectly competitive factor market.
B) upward sloping, the same as that for a firm buying factors of production in a perfectly competitive factor market.
C) downward sloping, unlike the horizontal curve for a firm buying factors of production in a perfectly competitive factor market.
D) horizontal, the same as that for a firm buying factors of production in a perfectly competitive factor market.