Jacob rents rooms in his hotel for an average of $100 per night. The variable cost per rented room is $20, to cover maid service and utilities. His fixed costs are $100,000 and his profit last year was $20,000. For Jacob, the contribution per unit is
A. $100.
B. $80.
C. $800.
D. $1,000.
E. It cannot be determined from the information provided.
Answer: B. $80.