19. The above table shows Priscilla's marginal utility from the two goods she consumes, pizza and Pepsi. A slice of pizza costs $4 and a can of Pepsi $2. Suppose Priscilla has $12 to spend. Which of the following leads Priscilla to switch her choices of pizza and Pepsi?
(A) an increase in Priscilla's income.
(B) an increase in the price of pizza to $6 per slice.
(C) a decrease in the price of Pepsi to $1 per can.
(D) All of the above will cause Priscilla to change her choices.