[单选题]
3. Which of the folloqd 10q)ysbqyr0i /*h iwing are factors9ltrtxga6x4 ,bc 8x1jv vl /,l involved in natural selection?
I. Intraspecific competition.
II. Environmental changes.
III. Overproduction of offspring.
IV. Selective breeding.
A. All of the above
B. I and II only
C. I, II and III only
D. I, III and IV only
