What is the ratio of the atomic radius of the 5th orbit in chlorine atom and 3rd orbit in Helium atom?

What is the ratio of the atomic radius of the 5th orbit in chlorine at

1.	What is the ratio of the atomic radius of the 5^th orbit in chlorine atom and 3^rd orbit in Helium atom?
A.	153:50
B.	50:153
C.	153:100
D.	100:153
Answer» C. 153:100