The first diffraction minimum due to the single slit diffraction is seen at $$\theta = 30°$$ for a light of wavelength $$5000\text{\AA}$$ falling perpendicularly on the slit. The width of the slit is

A

$$2.5\times 10^{-5}$$ cm

B

$$1.25\times 10^{-5}$$ cm

C

$$10\times 10^{-5}$$ cm

D

$$5\times 10^{-5}$$ cm