The correct sentence is:
"We have been waiting** for the train for the past one hour."**
### Explanation:
- The sentence requires the present perfect continuous tense because it talks about an action that started in the past and is still ongoing or relevant at the present time.
- The structure for the present perfect continuous is: Subject + have/has + been + verb-ing.
So, "We have been waiting" is the correct form, indicating that the action of waiting started in the past and continues into the present.