In a group discussion about James Fennimore Cooper, which sentence is most clearly using evidence from outside resources?

A.
One of James Fennimore Cooper's most enduring and emotional stories is The Last of the Mohicans.

B.
Stories like The Deerslayer show that James Fennimore Cooper was a product of the Romantic era, nothing more.

C.
According to Mark Twain's essay, "Fennimore Cooper's Literary Offenses," Cooper was completely overhyped.

D.
James Fennimore Cooper's Leatherstocking Tales is both surprisingly enlightened and prejudiced.

C.

According to Mark Twain's essay, "Fennimore Cooper's Literary Offenses," Cooper was completely overhyped.