For the existence of nitrogen in its stable molecular form,how many nitrogen atoms are required?

Which of these is not a ketone body?

$A$: In $PPP$ $(HMS)$,complete oxidation of one glucose molecule would produce $6CO_2$ molecules and $12$ $NADPH_2$ molecules.
$R$: It occurs in cytoplasm and chloroplast,in presence of $O_2$.

Which of the following is not correct with reference to fermentation and aerobic respiration?

Select the correct option for respiratory substrates.

The following is a simplified scheme showing the fate of glucose during aerobic and anaerobic respiration. Identify the end products that are formed at stages indicated as $A, B, C$ and $D$. Identify the correct option from those given below.