Question: A 1979 period children’s adventure film, directed by a man known for his socially critical directing style and for his socialist ideals, which are evident in his film treatment of social issues, was based off a novel by what author?
Sentence (from "Black Jack (1979 film)"): Black Jack is a 1979 period children’s adventure film, directed by Ken Loach and based on the Leon Garfield novel.
Relevant evidence: Yes