This is an on-call position. If hired, will that be an issue for you?

If this is an on-call position, it should have been noted in the job description, so it should be no surprise to you. Focus on letting the interviewer know that you understand the job requirements, and working on-call will not be an issue for you. The interviewer will see that you pay attention to detail and are a team player, which will benefit the company if hired.

If you want to be considered for the position, avoid saying you cannot be on-call. If you cannot be on-call on certain days, explain what outside obligation you have on those days and let the interviewer decide if they can work around your schedule.

"No, being on-call will not be an issue if you choose to hire me. I saw that in the job description and understand it is a job requirement. I have been on-call in previous positions and do not have a problem with it."