Suppose scientists believe that they've discovered a new planet. Which of the following must be true for the object they've found to qualify as a planet?

A. It must be shaped like an ellipsis.

B. It must have minimal gravity forces.

C. It must be capable of supporting life.

D. It must follow a closed orbit around a star.

The correct answer will be option-D.

Explanation:

According to the International Astronomical Union, a planet must satisfy three criteria to be a planet:

1. It must be an independent object which orbits around a star (in our cosmos-Sun).

2. It must have the mass to have its own gravity which forces it to have

a spherical shape

3. It must be large enough to dominate its orbit as its gravity should clear away any other objects.

Thus, option-D is the correct answer.

D. It must follow a closed orbit around a star