Answer:
Something that is persistent remains over time; this is a key characteristic of DDT, which also happens to be a pollutant/pesticide. DDT is able to persist in an environment (as a pollutant) in part due to a phenomenon known as biological magnification. In simpler terms. once DDT enters an ecosystem/trophic structure, it gets worse as you go up the trophic levels; in other words, this means that the worst effects/concentrations of the pesticide will be felt in the uppermost trophic levels (your consumers rather than producers).
The basis for this, however, lies in the fact that organisms of a trophic structure/ecosystem consume each other; they feed on each other to survive (e.g. consumers feeding on producers, higher-level consumers feeding on lower-level consumers, etc.). Thus, once DDT gets into an ecosystem, it can only persist and spread in that ecosystem. Hope this helps :)
B is the answer .............
<span>The Indian resistance was a social movement that sought to promote unity among native Americans in the continental United States in response to the white settlers who seized their land. It was unsuccessful.</span><span />
The Assembly line reduced time to produce a car, prices were lowered since manufacturing multiple parts that were interchangeably greatly profited from that venture as increasing production of all the goods like the petroleum industry, manufacturing industry and selling and distribution of said materials and resources now were easier. if Henry Ford had not invented the model t we would not have the Hoover Dam it needed tons of concrete and mater to be brought there fast as possible.