Question

The natural satellite of earth is-
(A) INSAT
(B) Moon
(C) Sputnik
(D) Aryabhata

Answer 1

Hint
INSAT is a satellite launched by ISRO. It is used to satisfy telecommunications, broadcasting and search and rescue operations.
The moon is an astronomical body which orbits the earth. It is the fifth largest satellite in the solar system.
Sputnik was the satellite which was launched by Soviet Union in 1957.
Aryabhata was the first Indian satellite. It was built and launched by ISRO.

Complete step by step answer
INSAT which can be expanded as Indian National Satellite System. It was built and launched by Indian Space Research Organization (ISRO). It was built in such a way that it can be a multipurpose satellite. It was commissioned in 1983. As it was launched by ISRO it is an artificial satellite.
Moon is an astronomical body which orbits the earth. It is the fifth largest satellite in the solar system. The alternative name for moon is Luna. The moon was formed 4.51 billion year just after the origin of the solar system. As it is not built by humans it is a natural satellite.
Sputnik is the artificial satellite which was launched by Soviet Union in 1957. Sputnik-1 was the first satellite launched. Then there were two successors of Sputnik which were Sputnik-2 and Sputnik-3. Sputnik is also an artificial satellite.
Aryabhata is the satellite which was named after the Indian Astronomer, Aryabhata. It was the first Indian satellite. As it was built and launched by ISRO. Aryabhata satellite is also an artificial satellite.
Therefore, the Moon is only a natural satellite of Earth. So, option (B) is the correct answer.

Note
The natural satellite is a satellite which orbits the planet of the body which is larger than itself. It is a satellite which is not man-made.
The artificial satellites which revolve around the planet but are built and launched by the space agency.