Organic Farm and Organic Valley compete on the market for whole milk. Below is the market demand schedule and total revenue generated. Both firms have the same constant cost structure, so maximizing total revenue maximizes profit. If Organic Farm and Organic Valley form a cartel (collude without cheating on each other), what will be the price per gallon of milk?

Quantity (in millions of gallons) Price (per gallon) Total Revenue (in millions)
0 $12 $0
1 $10 $5
2 $9 $10
3 $8 $15
4 $7 $20
5 $6 $25

A) $9
B) $8
C) $7
D) $6