Direction : Read the passage given below and answer the questions that follow by selecting the most appropriate option.

Experiments with the sulfonamides have made clear a fact about germs which is gaining increasing importance in fighting them. Germs, it seems, have the same ability as all the other living things gradually to change themselves to suit new conditions. But, as the generation of germs lasts only twenty, twenty-five or thirty minutes, before all the germs divide to form new ones, changes, that would take many years in animals, can be achieved by germs in a few hours. Perhaps then you give the attacking germ a dose of sulfonamides which upsets them somewhat but is not strong enough to prevent them from multiplying; if so, they very rapidly develop new powers which enable them to resist the effects of the drug. After this has happened, even the strongest dose will fail to disturb them.