Answer:
Principle of diminishing returns
Explanation:
In this case, Initial inputs of energy, water, fertilizer, and pesticides on high-yield crop varieties would produced high crop yields. As time goes on further adidtion of these same inputs of production would give the same or a lower yields of crops. Therefore, obeying the Principle of diminishing returns.
I believe the answer is A. A single origin of modern people and eventual replacement of archaic homo sapiens throughout Africa, Asia and Europe. Out of Africa model; asserts that modern humans evolved relatively recently in Africa, migrated into Eurasia and replaced all populations which had descended from Homo erectus. After Homo erectus migrated out of Africa the different populations became reproductively isolated, evolving independently, and in some cases like the Neanderthals, into separate species. Homo sapiens arose in one place, probably Africa. Homo sapiens ultimately migrated out of Africa and replaced all other human populations, without interbreeding modern human variation is a relatively recent phenomenon.
A) Virus.
Viruses force host cells to produce thousands of copies of the virus by attaching to the the host cell and transmitting its genetic material into it