Answer:
molCO2, because gCO2 cancels out, leaving mol CO2 as the only unit left to transfer over to the right-hand side.
Step-by-step explanation:
the units from the 86gCO2 cancels out with the units from 44 gCO2 cancel out (because they're the same and one is numerator, one is denominator), leaving just the molCO2