Answer:
The farthest one from the sun, the fourth one
Step-by-step explanation:
The gravitational force between any two objects is affected by the masses of the objects and the distance between them. The shorter the distance between two objects, the stronger the gravitational force of attraction is between them.
Since each planet has the same mass, the only factor affecting the strength of gravitational attraction is the distance between the planet and the star. Therefore, the planet that is the greatest distance from the star is experiencing the weakest force of gravitational attraction toward the star.