Ronda earned a large pay raise last year. She would like to spend some money this week on products that she could not afford last year. The law of demand states that when all other factors are being held constant: a) The higher the price of a good, the lower is the quantity demanded. b) The higher the price of a good, the lower is the quantity supplied. c) Price and quantity demanded are positively related. d) As one's income increases, the willingness to pay for another unit increases