Julie is selling candy bars to raise money for new band uniforms. Candy bar x sells for $2 and candy bar y sells for $3. The number of y candy bars Julia sells must be greater than or equal to three times the number of x candy bars she sells. She has at most 36 candy bars to sell.
What is the maximum revenue she can make?
A. $36
B. $99
C.$108
D. $216