求助NN一道语法

栖叶泠风

求助这道题，答案是C，可是C的for怎么看怎么别扭……

The Near Earth Asteroid Rendezvous (NEAR) spacecraft will orbit the asteroid Eros for a year, slowly moving closer to the surface of the object to make ever more precise measurements that scientists hope will enable them to understand how the solar system formed some four billion years ago.

1. to make ever more precise measurements that scientists hope will enable them to
   
   
   
2. to make ever more and more precise measurements, which scientists are hoping to enable them
   
   
   
3. for making ever more precise measurements, and scientists hope that they will be able to
   
   
   
4. with the purpose of making more precise measurements than ever, and which scientists hope will enable them to
   
   
   
5. in order to make more precise measurements than it ever did, and scientists are hoping they will be able to
   
   
   

clarry

- 大全总结第17条. able 只能用于人，不能物，见t234
- that不能指代句子。
- Athem指代不明确

栖叶泠风

可是我觉得C里面的they也有指代不清的嫌疑啊，我选的是A，这里的they的指代有什么讲究么？我感觉两个选项的they(them)都是差不多的

sweeet

这道题看起来风格很不对，C是有问题的，and链接的两件事有什么关系吗？原文是表目的的，C完全没有了，反而A看起来是最佳的了。