When an object is shot from the bottom of a long smooth inclined plane kept at an angle 60° with
horizontal, it can travel a distance 21 along the plane. But when the inclination is decreased to 30º and the same object is shot with the same velocity, it can travel 22 distance. Then 21 : 22 will be :

A. 1 : √2
B. √2 : 1
C. 1 : √3
D. 1 : 2√3