When an electron jumps from a level $n=4$ to $n=1,$ momentum of the recoiled hydrogen atom will be

• Correct answer
  A

  $6.8\times {10}^{-27}\mathrm{k}\mathrm{g}\mathrm{ }{\mathrm{m}\mathrm{s}}^{-1}$
• B

  $12.75\times {10}^{-19}\mathrm{k}\mathrm{g}\mathrm{ }{\mathrm{m}\mathrm{s}}^{-1}$
• C

  $13.6\times {10}^{-19}\mathrm{k}\mathrm{g}\mathrm{ }{\mathrm{m}\mathrm{s}}^{-1}$
• D

  zero

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