Correct Answer: 1-c, 2-d, 3-a, 4-b

Solution : The correct option is 1-c, 2-d, 3-a, 4-b.

An optical fibre is a thin, transparent rod that can carry light; it is typically composed of glass or plastic. The group's lone member is radioactive.

Radium is the heaviest known element of the alkaline earth. By use of his cathode ray tests from 1897.

Sir Joseph John Thomson discovered the electron.

Several forms of bacterial infections are treated using a class of medications known as penicillins. They are products made by fungi.