Two heavenly bodies S_(1) and S_(2), not far off from each other are ssen to revolve in orbit

Two heavenly bodies S_(1) and S_(2), not far off from each other are s

1.	Two heavenly bodies S_(1) and S_(2), not far off from each other are ssen to revolve in orbit
Answer» AROUND their COMMON centre of mass which are orbitrary with `S_(1)` fied and `S_(2)` moving rounds `S_(1)` with `S_(2)` fixed and `S_(1)` moving ROUND `S_(2)` ANSWER :A