this is a multiple choice question

Consider the following graph: Price p Quantity q The yellow shaded area represents: a) b) C) d) the \"deadweight loss\" associated with a monopolist's choice of its profit-maximizing output and price; the surplus that is gained by consumers if the monopolist switches from charging a single price to perfectly price discriminate among consumers (i.e., first degree price discrimination); the profit that is gained by the monopolist if the monopolist switches from charging a single price to perfectly price discriminate among consumers (i.e., first degree price discrimination); the profit lost by a monopolist if he is compelled through regulation to charge the competitive price; a) and c) are both correct