Industrial activity is often assumed to be a threat to wildlife, but that isn’t always so. Consider the silver-studded blue
butterﬂy (Plebejus argus): as forest growth has reduced grasslands in northern Germany, many of these butterﬂies have left
meadow habitats and are now thriving in active limestone quarries. In a survey of multiple active quarries and patches of
maintained grassland, an ecologist found silver-studded blue butterﬂies in 100% of the quarries but only 57% of the
grassland patches. Moreover, butterﬂy populations in the quarries were four times larger than those in the meadows.
It challenges a common assumption about the species under investigation in the research referred to in the text.
It introduces discussion of a speciﬁc example that supports the general claim made in the previous sentence.
It suggests that a certain species should be included in additional studies like the one mentioned later in the text.
It provides a deﬁnition for an unfamiliar term that is central to the main argument in the text.
Choice B is the best answer because it most accurately describes how the underlined portion functions in the text as a
whole. The ﬁrst sentence presents the general claim that industrial activity is not always a threat to wildlife. The underlined
portion of the sentence that follows suggests that the silver-studded blue butterﬂy is an example of wildlife thriving in areas
of industrial activity: active limestone quarries. Thus, the function of the underlined portion is to introduce a speciﬁc example
in support of the general claim in the previous sentence.
Choice A is incorrect. Although the ﬁrst sentence indicates that “industrial activity is often assumed” to harm wildlife, in the
case of the silver-studded blue butterﬂy the text mentions neither an assumption about this species nor any challenge to
such an assumption. Choice C is incorrect because the text mentions only one study: the “survey.” Additional studies are not
mentioned in the text. Choice D is incorrect because neither the underlined portion nor any other portion of the text provides
a deﬁnition for any of the terms used in the text’s argument.