I believe the answer is C
C. 64
Rewrite the logarithm:
8=x^.5
Solve by raising both sides of the equation to the power of the inverse (in this case, the inverse of .5, which is 2):
8^2=x^(.5*2)
64=x
28.23 is the volume of something if the diameter is 2 cm and the height is 9 cm.