Find the compound ratio of (1:2), (2:3) and (3:4) is  Choose the correct choice:
A) 1 : 2  B) 3 : 5  C) 5 : 7  D) 1 : 4  E) 2 : 1

Rationale: "required ratio = 1 / 2 * 2 / 3 * 3 / 4 = 1 / 4 = 1 : 4 answer is d"
Answer: D