Lyell's Book Principles of Geology,which Darwin Read on Board the H.M.S.Beagle,argued

Lyell's book Principles of Geology,which Darwin read on board the H.M.S.Beagle,argued in favor of which of the following concepts?

A) The processes that shape Earth today are very different from those that were at work in the past.
B) Earth's surface is shaped mainly by occasional catastrophic events.
C) Meteorite impacts may have been a major cause of periodic mass extinctions.
D) Earth's surface is shaped by natural forces that act gradually and are still acting.