Arrange the following respiratory substrates in the sequence of increase in R.Q. during aerobic respiration. 

A. Carbohydrates          B. Lipids                         C. Organic acids                                   D. Proteins

• A

  B → D → C → A           

• B

  D → B → A → C

• C

  B → D → A → C

• D

  A → B → C → D