GWD7-Q3 细节问题

GWD7-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.

A. rules intended to ensure that at least one nurse is assigned for every four patients put through triage in a hospital emergency room
B. 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
C. rules intending to ensure at least one nurse is assigned for every four patients in a hospital emergency room put through triage
D. 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
E. 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

答案是A，可否有人解释A里的''put through"是修饰什么的？
我的理解'put trough"是过去分词，修饰“rules",但是如果是这样，怎么能把‘put through" 放patient 后面呢？