Yasmin Co. can further process Product B to produce Product C. Product B is currently selling for $30 per pound and costs $28 per pound to produce. Product C would sell for $55 per pound and would require an additional cost of $31 per pound to produce. What is the differential cost of producing Product C?

a. $31 per pound

b. $28 per pound

c. $30 per pound

d. $55 per pound