Blue Company sells 3 types of umbrellas. Umbrella A sells for $20 and has variable cost of $9.00 per unit. Umbrella B sells for $17.00 and has variable cost of $12.00 per unit. Umbrella C sells for $9.00 and has variable costs of $6.00 per unit. Cindy sells in a mix of 2 units of A, 3 units of B and 5 units of C. What is the weighted average contribution margin per unit for Cindy?

A. $5.20

B. $13.60

C. $10.00

D. $6.33