The interviewer is asking this because they want to know if you lack any specific skills outlined in their job description. How you respond to this question will also reveal to the interviewer how much research you have done on the company before going into your interview.

If you are confident in all of the skills required for this role: 'I have read through your job description thoroughly and am excited about the opportunities this position offers. I am very skilled in all required areas.'

If you are not confident in all of the skills required for this role: 'I have read through your job description and am excited about the opportunities this position offers. Even though I do not have the three years of supervisory experience you ask for, I have one year of experience leading a team. I am quite well skilled in this area, and look forward to the opportunity to expand my skills.'