The answer is one over thirty two to the seventh power
B would be the closest answer
You can do 5+5+10, 6+6+8, 9+9+2, 4+4+12, 3+3+14, 2+2+16, 1+1+18. I believe these are all of them, so there are 7 ways.
You didn't include the actual number in inches.
Diameter is 2r, or 18.8 ft
Circumference is 2*pi*r, or 59.1 ft