Final answer:
Mary Barton by Elizabeth Gaskell is primarily about social class struggles in 19th-century England, depicting the harsh lives of the working class in Manchester.
Step-by-step explanation:
Mary Barton is a novel by Elizabeth Gaskell that was published in 1848. The correct choice for what the book was really about is a) Social class struggles in 19th-century England. The story is set in the industrial city of Manchester during the Victorian era, and it focuses on the life of the title character, Mary Barton, highlighting the difficult living and working conditions of the working class. Gaskell's novel is rich with social critique, addressing issues of poverty, class conflict, and the stark contrasts between the lives of the factory workers and mill owners. The narrative includes a love story and elements of a mystery, but these serve to underscore the novel’s central themes of social injustice and the struggles of the working class in industrialized cities.