Which of the following is the evidence to show that there must be a force acting on the Earth and directed towards the Sun?

Consider a binary star system consisting of two stars of masses $M_1$ and $M_2$ separated by a distance of $30 \text{ AU}$ with a period of revolution equal to $30 \text{ years}$. If one of the two stars is $5$ times farther from the centre of mass than the other, find the masses of the two stars in terms of solar masses.

The period of a satellite in a circular orbit around a planet is independent of

The relay satellite transmits the television signals continuously from one part of the world to another because its

Two stars of equal masses $M$ are orbiting in a circle of radius $R$. Their orbital time period is proportional to

Assertion $A$: An astronaut inside a massive spaceship orbiting around the Earth will experience a finite but small gravitational force.
Reason $R$: The centripetal force necessary to keep the spaceship in orbit around the Earth is provided by the gravitational force between the Earth and the spaceship.