A company makes and sells product X and product Y. Twice as many units of product Y are made and sold as that of product X. Each unit of product X makes a contribution of $10 and each unit of product Y makes a contribution of $4. Fixed costs are $90,000.

What is the total number of units which must be made and sold to make a profit of $45,000?

A. 7,500
B. 22,500
C. 15,000
D. 16,875