Name the scientists who were credited for showing the role of Penicillin as an antibiotic.

Which of the following pairs is incorrect?

Which of the following is mismatched?

Match the following columns:

Column-$I$	Column-$II$
$1.$ Silage	$a.$ Measure of water pollution level.
$2.$ Flocs	$b.$ Cattle feed.
$3.$ Biogas	$c.$ Bacteria associated with fungal filaments in water.
$4.$ $BOD$	$d.$ Anaerobic metabolism of organic waste.

Which one of the following pairs is wrongly matched?

Given below are two statements: one is labelled as Assertion $(A)$ and the other is labelled as Reason $(R)$ :
Assertion $(A)$ : $Spirulina$ is a microbe that can be used for reducing environmental pollution.
Reason $(R)$ : $Spirulina$ is a rich source of protein,carbohydrates,fats,minerals and vitamins.
In the light of the above statements,choose the most appropriate answer from the options given below: