This question has two parts. first, answer part a. then, answer part b.

part a

which statement tells what happened when antibiotics were first discovered?

most diseases were eliminated.

the number of viruses decreased.

© people became concerned about germs.

people began to use them too often.

part b

The answer is that most diseases were eliminated.

Explantion:

Penicillin was the beginning of the antibiotics era, it was discovered in 1940s by Alexander Fleming. Its discovery saved millions of live during World War II.  Antibiotics are produced by fungi and bacteria that are capable of inhibiting microbial species.

the tariff was created to protect industry in the northern part of the united states. industries in the north were being driven out of business by imported goods that were priced at a low rate. the goal was to protect these industries   by taxing the goods.