Using very powerful microscopes, scientists estimate the volume of some of the smallest bacterial cells to be 0.0090 cubic micrometers. What is the correct way to write this amount in scientific notation?

A. 9.0 x 103 cubic micrometers
B. 9 x 102 cubic micrometers
C. 9.0 x 10-3 cubic micrometers
D. 0.9 x 10-2 cubic micrometers​