a) – iii

b) – ii

c) – v

d) – i

The process of conversion of sugar into an acid or an alcohol by the action of microbes is called fermentation and it was first discovered by Louis Pasteur.

Robert Koch discovered the bacterium which causes anthrax.

Edward Jenner discovered a vaccine for small pox.

Alexander Fleming discovered penicillin antibiotic from the fungus Penicillium notatum.