Match the compounds given in column-$I$ with the number of carbon atoms present in them which are listed under column-$II$. Choose the answer which shows the correct combination of alphabets of the two columns.

Column-$I$	Column-$II$
$A$. Oxaloacetate	$p$. $6-C$ compound
$B$. Phosphoglyceraldehyde	$q$. $5-C$ compound
$C$. Isocitrate	$r$. $4-C$ compound
$D$. $\alpha$-Ketoglutarate	$s$. $3-C$ compound
	$t$. $2-C$ compound

• A
  $A = r, B = t, C = p, D = q$
• B
  $A = q, B = s, C = p, D = t$
• C
  $A = s, B = t, C = q, D = r$
• D
  $A = r, B = s, C = p, D = q$