Select the option that can be used as a one-word substitute for the given group of words.
A group of stars having a particular shape

Correct option is A

A constellation is a group of stars that forms a recognizable pattern or shape. Therefore, option (a) is the most appropriate one-word substitute for the given group of words.
· The other options can be defined as follows:
· Planet: a celestial body that orbits around a star and is not a satellite of a planet.
· Orbit: the path that a celestial object follows around another celestial object, such as a planet or star.
· Galaxy: a system of millions or billions of stars, together with gas and dust, held together by gravitational attraction.