Volume of sphere is:
V = 4/3 πr³
r = radius
π = 3.14
18 is your diameter. To find radius, divide the diameter by 2
18/2 = 9
plug in 9 for radius
V = 4/3 (3.14)r³
V = 4/3(3.14)(9)³
9³ = 729
V = 4/3(3.14)(729)
729(3.14) = 2289.06
V = 4/3(2289.06)
Note: first multiply 4, then divide 3
2289.06(4) = 9156.24
9156.24/3 = 3052.08
your closest answer is A
hope this helps