The interviewer asks this question to see that you have read the job description and determine what aspect of the role you like the most. Most job postings have many job duties you will be asked to perform. The interviewer wants to know what you like the most to see where your strengths lie and what motivates you in your job.
Focus on describing what you like most about the job and why. For example, you might like that you will be responsible for training all new employees and providing regular performance evaluations. Tell the interviewer why this particular job duty excites you.
