In an entrance test there are multiple choice questions. There are four possible answers to each question of which one is correct.The probability that a student knows the answer to a question is 90%. If he gets the correct answer to a question, then the probability that he was guessing is
(a) \(\frac{37}{40}\)
(b) \(\frac{1}{37}\)
(c) \(\frac{36}{37}\)
(d) \(\frac{1}{9}\)
Select the correct answer from above options