Being monoatomic, the atomic radius of noble gases are very small compared to covalent radius of other elements.

The correct option is B

False

Do you know how small is the size of an atom?

Its very small. Very very small.

It is in the range of ${10}^{-10}m$ is radius.

Therefore determination of atomic radius of an atom is very difficult because it is very small and electons surrounding the atom does not have a sharp boundary.

That's why, we always try to estimate the covalent radius.

Generally Noblegases do not react.

That's why they are monoatomic Being monoatomic and non-reactive, they do not have covalent radii. van der Waal's radii is estimated for noble gases, that is why their values are very large.