The sub-duplicate ratio of 1:9 is
Choose the correct choice from the following:
A) 4 : 3
B) 1 : 2
C) 1 : 3
D) 1 : 4
E) 2 : 3

Rationale: "root ( 1 ) : root ( 9 ) = 1 : 3 answer : c"
Answer: C