A beam of light of $\lambda =600 \mathrm{n}\mathrm{m}$ from a distant source falls on a single slit $1\mathrm{ }\mathrm{m}\mathrm{m}$ wide and the resulting diffraction pattern is observed on a screen $2\mathrm{ }\mathrm{m}$ away. The distance between first dark fringes on either side of the central bright fringe is:

• A

  $1.2 \mathrm{c}\mathrm{m}$
• B

  $1.2 \mathrm{m}\mathrm{m}$
• C

  $2.4 \mathrm{c}\mathrm{m}$
• Correct answer
  D

  $2.4 \mathrm{m}\mathrm{m}$

Hence, the correct answer is option: 'D'.