Which statement is enough to give the answer of question.

A and B together can complete a work in 8 days.B alone can do it in 20 days. What part of the work was carried out by A?

Statement-
I. A completed the job alone after A and B worked together for 5 days.
II. Part of the work done by A could have been done by B and C together in 6 days

1. If the data in statement I alone are sufficient to answer the question, while the data in statement II alone are not sufficient to answer the question
2. If the data in statement II alone are sufficient to answer the question, while the data in statement I alone are not sufficient to answer the question
3. If the data either m statement I alone or In statement II alone are sufficient to answer the question.
4. If the data in both the statements I and II together are necessary to answer the quesuon.