Which of the following sentences from the article best develops a central idea?
a
a year earlier, in april 1815, mount tambora, a volcano on the island of sumbawa in indonesia, erupted in a massive explosion.
b
"there's a lot of evidence that there were messianic cults and prophesies, and people thinking it was the end of the world," welt said.
c
"[shelley] actually takes on the burning, philosophical questions of her time . . she's asking questions about the nature of life, and giving life."
d
"the dissecting room and the slaughterhouse furnished many of my materials; and often did my human nature turn with loathing from my occupation."