If Acetyl Co A is the respiratory substrate, what is the Respiratory Quotient in aerobic respiration?

If Acetyl Co A is the respiratory substrate, it enters respiratory pathway at Krebs cycle and shows two decarboxylation (2CO2) reactions and four oxidation reactions. For oxidation of 3NADH and one FADH2, there is usage of 4 oxygen atoms or 2O2. Hence R.Q is 2/2 = 1 or unity.