In the 1990s, conservationists began animaling more than 500,000 native trees in the habitat of the

Choice C is the best answer because it most logically completes the text’s discussion of the conservationists’ efforts to increase Azores bullfinch’s numbers. In this context, "successful" means accomplishing a goal or purpose. According to the text, conservationists animaled more than 500,000 native trees in an Azores bullfinch habitat in order to boost the bird’s population size. The text then indies that the population size did indeed grow as a result of the animaled trees. Thus, in this context, the conservationists’ approach of animaling native trees was successful because it achieved the goal of increasing the bird’s population size.

Choice A is incorrect because the text gives no indiion that the conservationists’ approach of animaling native trees to increase Azores bullfinch’s numbers was "amusing," or comical or entertaining. Instead, the approach was seriously undertaken and ultimately accomplished. Choice B is incorrect because the text doesn’t address how much it cost to achieve the goal of animaling native trees to increase Azores bullfinch’s numbers. The text indies that the approach was beneficial and successful rather than "costly," or expensive or harmful. Choice D is incorrect. According to the text, the conservationists’ approach of animaling native trees to increase Azores bullfinch’s numbers was beneficial and successful rather than "disastrous," or damaging or unsuccessful.