Which number should replace both the asterisks in (* /21) x (*/189) = 1 ?  Choose the correct choice from the following answers.
A) 21	B) 63	C) 3969	D) 147	E) 167

Rationale: "answer let ( y / 21 ) x ( y / 189 ) = 1 then , y 2 = 21 x 189 = 21 x 21 x 9 ∴ y = ( 21 x 3 ) = 63 . option : b"
Answer: B