Use the Information Below to Answer the Following Question(s)

Use the information below to answer the following question(s) .
Express Bus Company operates a bus route that takes passengers from Cleveland to Chicago every day. Assume the bus tickets sell for $50 per rider; the bus line's variable costs are $35 per rider; and its fixed costs are $75,000 each month.
-What is the contribution margin per rider at Express Bus Company?

A) $15.00
B) $0.30
C) $35.00
D) $3.33