Grace Co. can further process Product B to produce Product C. Product B is currently selling for $23 per pound and costs $17 per pound to produce. Product C would sell for $42 per pound and would require an additional cost of $12 per pound to produce. What is the differential revenue of producing and selling Product C?

a.$19 per pound

b.$30 per pound

c.$25 per pound

d.$42 per pound