Identify correct pair :

Yeast have been used for the commercialproduction of

$I.$ ethanol                 $II.$ bread

$III.$ Toddy drink         $IV.$ Biogas

Choose the correct option

$A$ : After $24\; hours$ toddy becomes unpalatable.
$R$ : Toddy left for a few hours undergoes fermentation.

Penicillin was discovered by

First antibiotic isolated was