Satellites used for telecommunication relay are kept in a geostationary orbit. A satellite is said to be in such an orbit when: 1. The orbit is geosynchronous. 2. The orbit is circular. 3. The orbit lies in the plane of the Earth's equator. 4. The orbit is at an altitude of 22,236 km.

The correct answer is A because of the specific physical requirements for a geostationary orbit.

First, a geostationary orbit is a specific type of geosynchronous orbit where the satellite rotates at the same speed as the Earth, making it appear stationary from the ground. Therefore, statement 1 is correct.

Second, for a satellite to remain at a fixed point relative to the Earths surface without oscillating, the orbit must be perfectly circular and must lie exactly in the plane of the Earths equator. This makes statements 2 and 3 correct.

Third, statement 4 is incorrect because of the units used. A geostationary orbit is located at an altitude of approximately 35,786 kilometers. The number mentioned in the statement, 22,236, refers to the altitude in miles, not kilometers. Since the question specifies kilometers, statement 4 is technically false.