Product of two natural numbers is 11. Then, the sum of reciprocals of their squares is	Choose the correct choice
A) 290 / 289 B) 122 / 121 C) 290 / 90 D) 290 / 19 E) none of these

Rationale: "explanation : if the numbers are a , b , then ab = 17 , as 17 is a prime number , so a = 1 , b = 17 . 1 / a 2 + 1 / b 2 = 1 / 1 ( 2 ) + 1 / 11 ( 2 ) = 122 / 121 option b"
Answer: B