Negation of “Monu is in class $\mathrm{X}$ or Anu is in class $\mathrm{X}\mathrm{I}\mathrm{I}$” is

• A

  Monu is not in class $\mathrm{X}$ and Anu is in class $\mathrm{X}\mathrm{I}\mathrm{I}$
• Correct answer
  B

  Monu is not in class $\mathrm{X}$ and Anu is not in class $\mathrm{X}\mathrm{I}\mathrm{I}$
• C

  Either Monu is not in class $\mathrm{X}$ or Anu is not in class $\mathrm{X}\mathrm{I}\mathrm{I}$
• D

  None of these

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