A company operates a bus route that takes passengers from Vancouver to Calgary 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. a. What is the contribution margin per rider at this company? Oa $0.30 Ob. $35 Oc. $15 Od.$3.33 b. What is the contribution margin ratio at this company? Ca. 70% Ob 30% Oc. 3.33% Od.15% c. How many riders should they serve in a month to Break even? Oa. 2,143 Ob.5,000 Oc. 1,500 Od 2,000