An online retailer is considering three alternative services (denoted A, B and C) for making home deliveries of the orders it receives. Each alternative provides acceptable service, and each has a particular fixed and variable cost. Alternative A relies on automated aerial vehicles and has a monthly fixed cost of $8,000 and a variable cost of $2 per delivery. Alternative B uses automated ground vehicles and has a monthly fixed cost of $5,000 and a variable cost of $4 per delivery. Alternative C relies of truck delivery with drivers has a monthly fixed cost of $4,000 and a variable cost of $6 per delivery. The revenue received for each delivery is $11. (4 pts.) a) What is the breakeven point for Alternative B in monthly deliveries