Match the following bacteria/fungi of Column $I$ with their commercial products of Column $II$.

Column $I$	Column $II$
$A$. Lactobacillus	$p$. Butyric acid
$B$. Aspergillus niger	$q$. Acetic acid
$C$. Acetobacter aceti	$r$. Lactic acid
$D$. Clostridium butylicum	$s$. Citric acid

Select the code for the correct answer from the options given below.

• A
  $A-r, B-q, C-s, D-p$
• B
  $A-p, B-s, C-r, D-q$
• C
  $A-r, B-s, C-q, D-p$
• D
  $A-r, B-s, C-p, D-q$