⟩ Tell me if you had to deal with a parent each day whom just was not ever happy what would you do to make them happy?
The interviewer wants to see what kind of inter-personal skills you have. You may want to talk about being a good listener, making the parent feel like he/she has been heard, not reacting, being proactive and solution-oriented, and even giving the person the impression you like them (even if they don't like you) and to ask for their input.