Claudia has an income of $425 per week with which she purchases tests, good x, and other goods, good y, where the price of other goods is $1 per unit. Suppose that Claudia's preferences are convex (her MRSX,Y is a decreasing function of x and an increasing function of y).

Old policy: Claudia can buy up to five tests per week and pay $5 each at the government store. However, any additional test beyond the 5th costs $50 on the black market.

New policy: suppose the market for tests is decontrolled and the price is now $25 per test.

Suppose that, under the old policy, Claudia chose to purchase 4 tests per week. Which policy will she prefer? Explain and illustrate your answer with the two budget lines and Claudia's old choice.