If the ratio of the number of boys to that of girls in school B is 7: 6 and the ratio of the number of boys to that of girls in school D are 4 : 5, then what is the ratio of the number of boys in B to that of girls in D?

• A. 12 : 13
• B. 14 : 13
• C. 13 : 12
• D. 13 : 14