For a monopoly. what is the quantity effect? a) The change in total revenue caused by old customers now paving the new price. 0 b) The change in marginal revenue caused by old customers now paying the new price. c} The change in total revenue caused by the new customers now paying the old price. 0 d) The change in marginal revenue caused by the new customers now paying the new price. 0 e] The change in total revenue caused by the new customers now paying the new price