In a test, an examinee either guesses or copies or knows the answer to a multiple choice question with four choices. The probability that he makes a guess is $\frac{1}{3}$ and the probability that he copies the answer is $\frac{1}{6}$. The probability that his answer is correct given that he copies it is $\frac{1}{8}$. The probability that his answer is correct, given that he guesses it is $\frac{1}{4}$. The probability that he knew the answer to the question given that he correctly answered, is

• A

  $\frac{24}{31}$
• B

  $\frac{17}{24}$
• Correct answer
  C

  $\frac{24}{29}$
• D

  $\frac{29}{31}$

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