Q3:

The state has proposed new rules that would set minimum staffing levels for nurses, rules intended to ensure that at least one nurse is assigned for every four patients put through triage in a hospital emergency room.

1. rules intended to ensure that at least one nurse is assigned for every four patients put through triage in a hospital emergency room
2. rules with the intent of ensuring one nurse at least to be assigned for every four patients to be put through triage in a hospital emergency room
3. rules intending to ensure at least one nurse is assigned for every four patients in a hospital emergency room put through triage
4. with the intent of ensuring that at least one nurse should be assigned for every four patients in a hospital emergency room that are put through triage
5. and this is intended to ensure one nurse at least to be assigned for every four patients put through triage in a hospital emergency room

Answer: A

哪位nn指点一下，这个划线部分在句子中充当什么成分？rules后面的intended 是分词形式还是动词？实在看不明白这句。

谢谢先！