Which of Following Is Not a Condition That Must Be

Which of following is not a condition that must be met for a cartel to maximize its joint profits?

A) Total output by the cartel must be allocated among the member firms such that the individual firm's marginal costs are equal.
B) The cartel must produce the level of output at which its marginal revenues and marginal costs are equal.
C) The cartel must be operating in the inelastic portion of its demand curve.
D) Each member firm must employ the least-cost method of production.