The following text is adapted from the US. National ParkService's website article "The Redwoods of Coast and Sierra: Redwoods...contain neither (the burnable) pitch nor resin:furthermore, since the asbestos like bark grows to at least one foot in thickness.once the trees have reached maturity they are not easily killed. [T]hese trees may (remain vigorous for centuries) though their heart is burned out...The term "heartwood Is really a misnomer ...as (h)eartwood is composed of cells which have ceased to live. The outer layers of the wood of a tree, known as sapwood, are the live part of the wood... Since the Sierra Redwood does not sprout from the base, trees which have been killed by fire cannot continue to reforest the area. The Coust Redwood, however, reproduces abundantly by forming sprouts around the base of parent trees....[E]ven after as many as ten successive years of heavy burning of the stumps on a cut-over region sprouts have still continued to come up.... __ Which choice best describes the function of the underlined sentence in the text as a whole? Elimination Tool Select one answer A Itserves as contrast between the one type of Redwood found in the mountains (Sierra)and the other found along the Pacific (Coust) B It introduces the nature of the problem facing the forest service, the timber industry, environmentalists, andtourist alike. C Itidentifies the one thing that can finally succeed in overcoming the previouslyestablishedistrengths of the Redwood D It establishes the basis of the connection between Reducod characteristics described before it and those that follow.