Yasmin Co$.$ can further process Product B to produce Product C$.$ Product B is currently selling for $$32$ per pound and costs $$28$ per pound to produce. Product C would sell for $$60$ per pound and would require an additional cost of $$23$ per pound to produce. The differential cost of producing Product C is

a$.$ $$23$ per pound

b$.$ $$28$ per pound

c$.$ $$60$ per pound

d$.$ $$32$ per pound