The Budget Constraint for a Consumer Who Only Buys Apples

The budget constraint for a consumer who only buys apples (A) and bananas (B) is P_AA + P_BB = I where consumer income is I, the price of apples is P_A, and the price of bananas is P_B. To plot this budget constraint in a figure with apples on the horizontal axis, we should use a budget line represented by the slope-intercept equation:

A) A = -I/P_A + (P_B/P_A) B
B) A = I/P_A - (P_B/P_A) B
C) B = -I/P_B + (P_A/P_B) A
D) B = I/P_B - (P_A/P_B) A