Mr. Rochester would be a dynamic character. A dynamic character is one who undergoes change and growth in a story. As the question states, he starts the story as an angry, frustrated, and mysterious character, but ends up softened and altered by Jane Eyre. Remember: a minor character is one who does not influence the story much; a static character is one who remains the same throughout a story; a flat character is synonymous with a static character. So, you can eliminate all of those, giving you another path to the right answer. Hope this helps.
