For Any Object Orbiting the Sun,Kepler's Law May Be Written

Multiple Choice

For any object orbiting the Sun,Kepler's law may be written T² = kr³.If T is measured in years and r in units of the Earth's distance from the Sun,then k = 1.What,therefore,is the time (in years) for Mars to orbit the Sun if its mean radius from the Sun is 1.5 times the Earth's distance from the Sun?

A) 1.8 years
B) 2.8 years
C) 3.4 years
D) 4.2 years