The interviewer is trying to find out your key interests and whether the job offered has responsibilities you will dislike. Focus on what you particularly enjoyed in your last role and what you learned from it, drawing parallels to the new role. When addressing what you disliked, be conscious not to criticize your last employer. Choose an example that does not reflect on your skills (such as company size) or which reveals a positive trait (such as your dislike for prolonged decision making).