A can do a piece of work in 4 days. B can do it in 8 days. With the assistance of C they completed the work in 2 days. Find in how many days can C alone do it? Select.
A) 22 days
B) 8 days
C) 67 days
D) 1 days
E) 18 days

Rationale: "c = 1 / 2 - 1 / 4 - 1 / 8 = 1 / 8 = > 8 days answer : b"
Answer: B