[单选题]
2. There are many different domestihhwxk*f ygy +*+*(c ylcated breeds of cattle descended from th-crhh;m; a 4dpe wild ox about 10,500 years ago. What is the term that describes the formation of new breeds of farmed cattlh-h cm;rd4p; ae?
A. Inbreeding.
B. Selective breeding.
C. Natural selection.
D. Speciation.
