If Joint Profits Are to Be Maximized in an Oligopolistic

If joint profits are to be maximized in an oligopolistic industry with a homogeneous product, the firms

A) have no individual incentive to cheat on the agreement.
B) can produce whatever output they want at the agreed- upon price.
C) must form a cartel in order to be legal.
D) need to determine the share of output each firm will produce.
E) none of the above -- differentiated products are required for joint- profit maximization in oligopoly.