The correct answer of this question : The planet outside of our solar system.
EXPLANATION:
The extra-solar planet is the planet which is present beyond our solar system. It is also known as exoplanet.
Just like our solar system planets like the earth,Mars, Jupiter etc, the exoplanet is also a part of another solar system. The planets revolves around their sun i.e other star in different orbits. This star is the centre of their solar system.
Hence, the exact explanation for the exoplanet is the planet situated beyond our solar system, and revolves around any other centrally situated star.
