The Products of the Combustion of Acetone with Oxygen Are

The products of the combustion of acetone with oxygen are shown in the following equation:
__ CH₃COCH₃ + __ O₂ → __ CO₂ + __ H₂O
When properly balanced,the equation indicates that ____ mol of O₂ are required for each mole of CH₃COCH₃.

A) 4
B) 6
C) 3.5
D) 7
E) 2