The correct option is A Chemicals which would adversely affect the invading bacteria but not the host, can be used for the treatment of diseases caused by the bacteria.
Following was the idea of Paul Ehrlich.
Chemicals which would adversely affect the invading bacteria but not the host, can be used for the treatment of diseases caused by the bacteria.
Paul Ehrlich was a German Bacteriologist. He prepared compounds containing arsenic for treating syphilis. In 1908, he got the Nobel Prize for discovering arsphenamine (salvarsan) to kill syphilis bacteria.
He also worked on azo dyes containing −N=N− linkage similar to −As=As− linkage in salvarsan, and prepared antibiotic protonsil.