Always ensure to review the job posting before the interview to familiarize yourself with the travel requirements.

Should an interviewer ask such a question, it is highly likely you will have to travel. As such, the interviewer will expect you to have applied for the position after carefully reading it, in turn expecting you to be able to travel as needed.

Should these requirements be mentioned on the job posting and should you answer in the negative, you may be immediately disqualified. Not only would you not meet a crucial requirement for the role, this would also show you did not carefully read the job posting before applying and the interviewer may think you simply applied to get any job - and as such, you are not serious about working for this employer specifically and/or will not commit.