在城市用地分类与规划建设用地标准中，下列有关的原则中哪项是正确的（）

A.老年活动中心用地应归类为游乐用地 

B.科学研究、勘测设计、观察测试、科技信息和科技咨询等机构，以及附设于单位内的研究室和设计室等的用地应归类为教育科研设计用地 

C.高等学校、中等专业学校，中学，科学研究和勘测设计单位机构等用地应归类为教育科研设计用地 

D.公安局、公安分局、监狱、拘留所、劳改所以及安全保卫部门用地，应归类为保安用地

Excavations at a Mayan site have uncovered jewelry workshops located some distance from the center of the site on roads radiating outward from the center. Since the nobility lived only in the area of the center, archaeologists conclude that these workshops made jewelry, not for the nobility, but for a middle class that must have been prosperous enough to afford it.
The archaeologists’ argument assumes which of the following about the artisans who worked in the workshops

A．They were themselves prosperous members of a middle class.

B．They lived near their workshops.

C．Their products were not made from the same materials as was jewelry for the nobility.

D．They worked full-time at making jewelry and did not engage in farming.

E．(E) They did not take the jewelry they had made in the workshops to clients who were members of the nobility.