A slit of width $$a$$ is illuminated by parallel monochromatic light of wavelength $$\lambda$$. The value of $$a$$ at which the first minimum of the diffraction pattern will form at $$\theta = 30^\circ$$ is

A

$$\frac{\lambda}{2}$$

B

$$\lambda$$

C

$$2\lambda$$

D

$$3\lambda$$