A certain reptile species is a herbivore and exists only on an isolated island. Which of the following would most likely result in the extinction of the reptile species over a period of twenty thousand years?
A. The reptile species produces many offspring with many unique traits, and the vegetation remains constant.
B. The reptile species produces few offspring with some unique traits, and the vegetation remains constant.
C. The reptile species produces few offspring with no unique traits, and the vegetation changes quickly.
D. The reptile species produces many offspring with some unique traits, and the vegetation changes slowly.