In Young’s double slit experiment the separation d between the slits is 2 mm, the wavelength $$\lambda$$ of the light used is 5896 A and distance D between the screen and slits is 100 cm.It is found that the angular width of the fringes is $$0-20^\circ$$ To increase the fringe angular width to $$0.21^\circ$$ (with same $$\lamda$$ and D) the seaparation between the slits needs to be changed to

A

1.7 mm

B

2.7 mm

C

1.9 mm

D

1.8 mm