Which quantity remains constant in the orbital motion of the Earth around the Sun?

$A$ planet of mass $m$ moves around the sun of mass $M$ in an elliptical orbit. The maximum and minimum distances of the planet from the sun are $r_1$ and $r_2$ respectively. The time period of the planet is proportional to ..........

$A$ body revolves around the sun $27$ times faster than the earth. What is the ratio of their orbital radii?

The distance of a planet from the sun is $5$ times the distance between the earth and the sun. The time period of the planet is

The kinetic energies of a planet in an elliptical orbit about the Sun,at positions $A, B$ and $C$ are $K_A, K_B$ and $K_C$,respectively. $AC$ is the major axis and $SB$ is perpendicular to $AC$ at the position of the Sun $S$ as shown in the figure. Then

The distances of Neptune and Saturn from the Sun are nearly $10^{13} \ m$ and $10^{12} \ m$ respectively. Assuming that they move in circular orbits,their periodic times will be in the ratio: