A firm has three different investment options, each costing $10 million. Option A will generate $12 million in revenue at the end of one year. Option B will generate $15 million in revenue at the end of two years. Option C will generate $18 million in revenue at the end of three years. Which option should the firm choose?
A. Option A
B. Option C
C. Option B
D. The answer depends on the rate of interest, which is not specified here.