For a fundraiser, the Lexington High School football team is making ice cream sundaes, They can buy chocolate ice cream for $15 per gallon and vanilla ice cream for $10 per gallon. They need at least 25 gallons and have a budget of $300. The lines x + y = 25 and 15x +10y= 300 are graphed in the coordinate plane below where and represent the number of gallons of chocolate and vanilla ice cream, respectively. Which region represents all the numbers of gallon of each flavor that the team could buy?

Region A
Region B
Region C
Region D