Justin has 100 feet of fence to make a rectangular dog pen. What dimensions of the rectangle will provide the largest pen for the dog?
A20 ft by 30 ft
B25 ft by 25 ft
C35 ft by 15 ft
D40 ft by 10 ft
A20 ft by 30 ft
B25 ft by 25 ft
C35 ft by 15 ft
D40 ft by 10 ft