Which of the following is an example of artificial selection?

A. The finches that Darwin noticed on the Galapagos Islands that had developed different shaped beaks based on selective pressures from the environment.
B. The tortoises Darwin noticed on the Galapagos Islands that had developed different sized necks based on selective pressures from the environment.
C. The pigeons Darwin noticed that had traits such as reverse neck feathers that had been selectively bred by humans.
D. The fossils that Darwin noticed from huge animals like Glyptodon, a giant armadillo, that looked very much like living species.