Shelley states that, "invention . . does not consist in creating out of void, but out of chaos." what chaos most likely enabled her to invent the characters of her ghost story?

a. a combination of lord byron's poetry and her husband's insistence on writing
b. a combination of depression, personal loss, and a desire for fame
c. a combination of polidori's story and delirium caused by an illness
d. a combination of a vividly terrifying nightmare and a discussion of darwin