Correct Answer: 8T

Solution : The correct option is 8T .

Kepler's third law, which connects the period (T) of revolution to the radius (R) of the orbit, governs the period of revolution of a planet in a circular orbit. According to Kepler's third law, the radius of the circular orbit in this instance is equal to the cube of the semi-major axis, and the square of the period of revolution.

The period of revolution in an orbit with a radius of 4R will be 8 times the original period.