The correct answer is option B) "The protagonist in The Circuit is Panchito". In the novel "The Circuit: Stories from the Life of a Migrant Child" by Francisco Jimenez, it is described the story of Panchito, a child that had a journey from Mexico to the United States. This is an autobiographical story told by the author, at which it can be concluded that Panchito is the protagonist.
HER in the sentence could be describing Deirdre or Winifred, because it is unclear. By adding Winifred's into the sentence, it is clear that the book is Winifred's favorite and not Deidre's.