The table shows the demand curve for barrels of spring water sold by James, a monopolist. Water Monopoly Price per barrel Number of barrels $16 0 15 1 14 2 13 3 12 4 11 5 10 6 9 7 8 8 7 9 6 10 If James lowers his price from $7 to $6, the total effect from both the quantity effect and the price effect is: positive marginal revenue of $3. negative marginal revenue of $3. positive marginal revenue of $6. no change in marginal revenue