JEE Math Practice Question

For a regular polygon, let $$r$$ and $$R$$ be the radii of the inscribed and the circumscribed circles. A $$false$$ statement among the following is :

1. A.There is a regular polygon with $${r \over R} = {1 \over {\sqrt 2 }}$$
2. B.There is a regular polygon with $${r \over R} = {2 \over 3}$$
3. C.There is a regular polygon with $${r \over R} = {{\sqrt 3 } \over 2}$$
4. D.There is a regular polygon with $${r \over R} = {1 \over 2}$$