On which day in July was definitely Mohan’s mother’s birthday?
I. Mohan correctly remembers that his mother’s birthday is before eighteenth but after twelfth July.
II. Mohan’s sister correctly remembers that their mother’s birthday after fifteenth but before nineteenth July.

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

 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.

 the data either in statement I alone or in statement II alone are sufficient to answer the question

 the data given in both the statements I and II together are not sufficient to answer the question

 the data in both the statements I and II together are necessary to answer the question