Assume That a Job Package Is Characterized by the Pair

Assume that a job package is characterized by the pair (w,z) where w is the wage,and z is a single undesirable non-wage job attribute.A firm's iso-profit curves:

A) are finite in number.
B) correspond to exactly zero economic profits.
C) represent a set of (w,z) pairs that yield a particular equal level of profits.
D) are convex to the origin.
E) are strictly increasing.