Answer:
Family
Explanation:
The Mysteries of Udolpho as written by Ann Radcliffe is a novel that has its settings in 1584, somewhere in France and northern Italy and it narrates the situation a young French maiden Emily St Aubert found herself in after her father's demise.
The developed theme is that of Family as she is kept captive in a castle by Signor Montoni who married her aunt Madame Cheron. She faces further family conflict from her aunt Cheron who refuses her from marrying the man she wants.
