Correct option is (a) True
To elaborate: A geosynchronous satellite is a satellite with a time period of 24 hours. It may or may not lie in the equatorial plane and hence it may not always appear fixed in the sky. However, it will return to the same position after every 24 hours.
Therefore, a geosynchronous satellite orbiting the earth in the equatorial plane is a geostationary satellite.
Every geostationary satellite is a geosynchronous satellite but not vice versa.