On every evening, a student either watches TV or reads a book. The probability of watching TV is $\frac{4}{5}$. If he watches TV, the probability that he will fall asleep is $\frac{3}{4}$ and it is $\frac{1}{4}$ when he reads a book. If the student is found to be asleep on an evening, the probability that he watched the TV is

• A

  $\frac{11}{13}$
• Correct answer
  B

  $\frac{12}{13}$
• C

  $\frac{2}{13}$
• D

  $\frac{4}{13}$

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