Which examples of artificial selection are caused by human activity without people even realizing it? a. an increase of tuskless Asian elephants because of ivory poaching
b. growing human organs from pig stem cells because of increased research on stem cell therapy
c. a decrease in rams’ horn size because of hunters’ preference for long-horned rams
d. cows producing milk with more protein because of genetic engineering
e. chickens producing more meat because of selctive breeding