A rod of 2 cm diameter and 30 cm length is converted into a wire of 3 metre length of uniform thickness. The diameter of the wire is:

A

$$\frac{2}{10}$$ cm

B

$$\frac{2}{\sqrt{10}}$$ cm

C

$$\frac{1}{\sqrt{10}}$$ cm

D

$$\frac{1}{10}$$ cm