Maritza, Kerstin, and Hermine are collecting books. Maritza has twice as many books as Kerstin. Hermine has 15 fewer books than Kerstin. The three girls have 113 books in all. How many books does Kerstin have? Which answer shows the correct equation, as well as correct answer to the question, for this situation, where m represents the number of books that Maritza has?

A. The equation is m+12m+(12m−15)=113. Kerstin has 32 books.
B. The equation is m+12m+(12m−15)=113. Maritza has 32 books.
C. The equation is 12m+(12m−15)=113. Kerstin has 64 books.
D. The equation is 12m+(12m−15)=113. Maritza has 64 books.
E. The equation is 2m+m+(m−15)=113. Kerstin has 16 books.