A firm uses two factors of production. Irrespective of how much of eac

A firm uses two factors of production. Irrespective of how much of each factor is used, both factors always have positive marginal products which imply that

A) isoquants are relevant only in the long run
B) isoquants have negative slope
C) isoquants are convex
D) isoquants can become vertical or horizontal
E) none of the above

ANSWER

B