The duplicate ratio of 6:4 is?	Choose the correct choice from the following options.
A) 1 : 2 B) 9 : 4 C) 1 : 8 D) 1 : 18 E) 1 : 13

Rationale: "36 ^ 2 : 4 ^ 2 = 36 : 16 = 9 : 4 answer : b"
Answer: B