Question

In the diagram, planets A, B, and C have the same mass. Which of these statements is true about the motion of these planets?

Answer 1

The second option is correct, because planet A has the shortest orbit and planet C has the longest one.

Answer 2

A,B,C are three planets with the same mass,then it means they have also the same gravity,so what matters here is the distance between the Sun,more exactly,their orbits.
⇒ The shorter the distance from the Sun, the more a planet completes an orbit. ⇒ Correct affirmation : Planet A will take the shortest time to complete an orbit, while planet C will take the longest time.

The first affirmation is false because the planet A is the closest to Sun,so logically,it will complete the orbit faster than the others.

The affirmations 3 and 4 are incorrect because their gravity is equal and because the distance between the planets and the Sun differs from one planet to another.