Suppose All of the Firms in a Perfectly Competitive Industry

Suppose all of the firms in a perfectly competitive industry form a cartel and agree to restrict output,thereby raising the price of the product.Individual Firm A will gain the most from the existence of the cartel if

A) all firms revert back to their competitive outputs.
B) no firms restrict output.
C) all firms,except Firm A,cooperate and restrict output.
D) Firm A restricts output,while the other firms do not.
E) all firms,including A,cooperate and restrict output.