TOEFL Reading: ETS-TOEFL阅读机经 - Y37E42K6773278V3L$

Which of the following most accurately reflect the relationship between paragraph 6 and a topic discussed in paragraph 5? A. Paragraph 6 discusses a series of events that calls into question the theory that plants and animals were raised for purposes of trade. B. Paragraph 6 presents evidence supporting the claim that many sites of agricultural innovation were located near trade centers. C. Paragraph 6 identifies problems that led to the raising of plants and animals as the primary source of sustenance. D. Paragraph 6 traces negative developments that arose possibly as a result of raising plants and animals for trade.