Choose the method of pay that would result in the most earnings for one month on sales of $60,000.a.Straight commission of 6% on all sales.b.Monthly salary of $1,500 plus 3% commission on all sales.c.Graduated commission of 4% on the first $50,000 in sales and 10% on anything over that.d.Graduated commission of 5% on the first $40,000 in sales and 9% on anything over that.