Green Co. incurs a cost of $15 per pound to produce Product X, which it sells for $26 per pound. The company can further process Product X to produce Product Y. Product Y would sell for $30 per pound and would require an additional cost of $10 per pound to be produced. The differential cost of producing Product Y is.

a. $15 per pound

b. $26 per pound

c. $10 per pound

d. $30 per pound