When Balanced with Smallest Set of Whole Numbers, the Coefficient $\rarr$

Multiple Choice

When balanced with smallest set of whole numbers, the coefficient of O₂ in the following equation is __ C₂H₄ + __ O₂ $\rarr$ __ CO₂ + __ H₂O

A) 1.
B) 2.
C) 3.
D) 4.
E) 6.