Final answer:
The woman who arrives unannounced at Schindler's apartment in 'Schindler's List' is b. Schindler's wife, Emilie Schindler. This event helps add depth to his character in the movie's narrative.
Step-by-step explanation:
The woman who arrives unannounced at Schindler's apartment door in the movie Schindler's List is Schindler's wife, Emilie Schindler. The character of Oskar Schindler, a German industrialist, is depicted as having a complex personal life, and the sudden arrival of his wife highlights this aspect of his character. In the context of the film and the historical events it portrays, such scenes contribute to the narrative by adding depth to the characters and their relationships during a tumultuous period in history.