My husband is asking me to move to his hometown and take care of his ailing parents. While I don't want to run away from my duty as a daughter-in-law staying in a small town would not be good for the education of my six-year-old son. how do I explain this to my husband without hurting him?

Let him know your concerns and maybe suggest an alternative. Your in laws could move to your place instead. That way, you get to stay put and your husband gets to be around to take care of your in laws as well. You can also suggest that where you stay have better medical facilities compared to a small town and this could be useful when dealing with ailing elderly parents.