TOEFL Reading: ETS-TOEFL阅读机经 - AEYH73G5E5VZL7C2L$

In paragraph 1, all of the following are mentioned as factors that contributed to the decline of the agricultural economy in the fourteenth century EXCEPT A. an increase in rain and wind B. a shortened growing season C. the investment of capital in areas other than agriculture D. a significant drop in temperature