A and B together can do a work in 7 days. If A alone can do it in 56 days. In how many days can B alone do it?	Choose the correct choice from the following answers:
A) 11
B) 8
C) 21
D) 20
E) 25

Rationale: "b 8 1 / 7 â € “ 1 / 56 = 1 / 8 = > 8"
Answer: B