9) Peter consumes goods X and Y. The price of good X is Px and the price of good Y is Py, Peter's income is I. If both prices increase by 50%, and Peter's income decreases by 50% then the

A) slope of the budget constraint will increase

B) slope of the budget constraint will decrease.

C) budget constraint will be unchanged.

D) budget constraint will shift outward in a parallel fashion.

E) budget constraint will shift inward in a parallel fashion.