TOEFL Listening: TPO-TOEFL阅读TPO - 90N455UQTG3W24_9N$

It can be inferred from paragraph 4 that it was difficult for people to change from farming back to hunting and gathering because A. people had become more used to different types of food B. climatic conditions were no longer favorable for hunting and gathering C. populations had become too large to be supported by hunting and gathering D. the farmer's sedentary life was easier than the hunter-gatherer's nomadic life