Scientific investigations often lead to the formulation of new scientific questions. the observations charles darwin made during his time aboard the h. m.s. beagle prompted him to ask which question? do living organisms change over time and, if so, how? are the finches of the galapagos islands the same as those on the mainland? can selective breeding occur in nature? can the accumulation of gradual changes in a population lead to a new species over time?

Charles Darwin is known as the man behind the concept of natural selection - that some traits that give relative advantage would appear more and more often, eventually changing the species over time. The correct answer is thus the last one: "the accumulation of gradual changes in a population leads to a new species over time". It especially can't be the first option - we know that organisms chance over time (children become adults) - so we didn't need Darwin to realize that, this is somehting that people have understood for a long time. His discovery was connected to selective breeding, but his major insight was gradual evolution, not the breeding itself.

They became more resistant.