How many boys are there in the class ?
A. The class has total 45 children and ratio of boys to girls is 4 : 5.
B. The ratio of girls to boys is 4 : 5 and boys are nine more than the girls.

If the data in statement B alone are sufficient to answer the question while the data in statement A alone are not sufficient to answer the question.

If the data in statement A alone are sufficient to answer the question, while the data in statement B alone are not sufficient to answer the question.

If the data either in statements A alone or in statement B alone are sufficient to answer the question.

If the data in both the statements A and B together are not sufficient to answer the question.