The acid obtained from the fungus $Aspergillus$ $niger$ is .......

Chloromycetin is obtained from

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.

Which organism is rich in riboflavin?

Assertion $A$: Fungi are used to ripen Roquefort cheese.
Reason $R$: $Propionibacterium$ $sharmanii$ is used for Swiss cheese.
Which option is correct for Assertion $A$ and Reason $R$?

What is synthesized by microbes in the industrial sector?