Use the Following Statements to Answer This Question

Use the following statements to answer this question:
I.In a perfect M&M world with corporate taxes, WACC decreases linearly with the increase in debt in the company.
LI.In a perfect M&M world with corporate taxes, the slope of the WACC is proportional to debt.

A) I and II are correct.
B) I and II are incorrect.
C) I is correct and II is incorrect.
D) I is incorrect and II is correct.