Question

what is a star? *
a planet that gives off light
a large, glowing ball of gas that generates energy through nuclear fusion
a rock floating in space
a cloud of gas and dust

Explanation:

A star is a large celestial body. Planets do not generate their own light (they reflect it). A rock floating in space is an asteroid or meteoroid. A cloud of gas and dust is a nebula. Stars are large, glowing balls of gas (mainly hydrogen and helium) that produce energy via nuclear fusion in their cores.

Answer:

A large, glowing ball of gas that generates energy through nuclear fusion