Answer:
In contrast, major disturbances include large-scale wind events (such as tropical cyclones), volcanic eruptions, tsunamis, intense forest fires, epidemics, ocean temperature changes stemming from El Niño events or other climate phenomena, and pollution and land-use conversion caused by humans.
Explanation:
Controlled population growth.
Explanation:
US is a highly developed country and it has expansive infrastructure and highly mechanized agricultural equipments. So first option is not a choice. Second, access to chemical fertilizers and pesticides in a country with such advanced agriculture infrastructure is very easy. Third US is well known for using GM crops.
US does not have a controlled population growth because if not the birth rate then migration of people to US is a major concern for that country. Thus, this will be a correct choice for the given question.