"Do it" is quite a rude thing to say. Why is somebody speaking to you like this? You could say, "OK" if you want to do it. You could say "Do it yourself" if you don't want to. You could say "Why?" if you want a reason. You could say "Don't speak to me like that" if you want to tell them to stop being rude. There are so many possible replies.

Hi Amal, Actually, it depends on you. If you want to do it, you can say 'I will' or ' okay' or 'sure'. Otherwise, you can say ' sorry I can't ' or 'I won't ' and if you are angry with her or him you can say ' Who are you to order me?! ' 😂

Depends. If you want to do it, you can say "I will."

Depends on you. If there is something that you want to do then say " I'll " Otherwise just say "no"