Other Things Equal, Cartels and Similar Collusive Arrangements Are Easier

Other things equal, cartels and similar collusive arrangements are easier to establish and maintain

A) when there are ample opportunities for the firms to make secret price concessions to selected buyers.
B) during periods of business-cycle stability and full employment.
C) when the demand and cost conditions of the participating firms differ substantially.
D) when the number of firms is relatively large.