Which statement is enough to give the answer of question.

The average age of teacher and students in a class is 3 years more than the average age of students. what is the age of the class teacher?

Statement-
I. There are 11 students in the class.
II. The average age of teacher and students is 14 years.

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 im statement I alone are not sufficient to answer the question
3. If the data in both the statements I and II together are necessary to answer the question
4. If the data in both the statements I and II together are not sufficient to answer the question