You will be given a definition of a task first, then some input of the task.
In this task, you will be presented with a text, a pronoun from the text, and two candidate names. You should determine what the pronoun refers to and classify the answers into A, B, or Neither. A and B here are referring to option A and option B. Position of the pronoun in the text is showed within two "_"s.

Their sons Leo and Mike also entered the family business after making their own forays into children's publishing as an author and illustrator, respectively. In the 1990s, the men worked on the Berenstain Bears ``Big Chapter Book'' series (published under the names Stan and Jan Berenstain). Following Stan's death from lymphoma in 2005, Mike collaborated with _his_ mother on writing and illustrating Berenstain Bears installments, while Leo has been involved with the business side of the franchise. <sep>, Pronoun: his <sep>, A: Stan <sep>, B: Mike
Output:
B