The correct option is A 1
Respiratory quotient (RQ) is ratio of volume of carbon dioxide evolved to volume of oxygen consumed. RQ of carbohydrates is 1.
C6H12O6+6O2Glucose⟶6CO2+H2O+ATP
RQ=6CO26O2=1
Respiratory quotient is less than 1 when the substrate is fats or proteins. It is higher when the cells do not have access to oxygen. Respiratory quotient is zero during incomplete oxidation.