Answer:
A. les duelen
Step-by-step explanation:
les duelen means mutiple and in the end of the sentence it says both of their arms form noth people hurt so this would be the correct way to say it. Le deule or option b means one person. Option C les duelen means multiple people but only one thing hurts. Last option, te duelen is like you are talking to the person and are asking if it hurts.