Mary Shelley says she conceived the idea of "Frankenstein":

A. while watching a frightening storm
B. after listening to a discussion about the nature of the creative process.
C. after visiting a morgue.
D. when she thought of a better ending to Polidori's story.

I'm stuck between B and D?

Actually there was bad weather, they were reading German ghost stories, talking about ghoulish things and then decided to see who could write the best ghost story.

Sra