A start-up company manufactures two products: X is sold for $5 with variable cost of $3 each; Y is sold for $8 with variable cost of $4 each. An annual fixed cost of $10,000 is projected. The marketing department estimates a 3:1 ratio between X and Y. How many units of X must be sold to break even for the first year of operation?

a. 3,600.

b. 3,000.

c. 1,500.

d. 1,000.