A and B together can complete a task in 1.2 days. However, if A works alone, completes half the job and leaves and then B works alone and completes the rest of the work, it takes 2.5 days in all to complete the work. If B is more efficient than A, how many days would it have taken B to do the work by herself?

A

1.5

B

1.8

C

2.0

D

2.2