Answer:
I will say D is the best option.
Step-by-step explanation:
D. Do the chores for them at first, so they can observe a model. Why? Because if you reward them before or after, they will take advantage of this and maybe invent an excuse for not doing chores before or they will always expect a gift after they finish. Then, if you punish them every time you asked them to do something they will get scared and they will not be willing to do it in a good way. So, I think the best option is D because it is important for them to see their parents do the chores at home and then the parents can teach them the importance of organizing everything, and in the future, they will do the chores by their own not forcing or rewarding them because of something they must do all their lives.