Although all of the options are sensitive information for a person, your mother's maiden name is something that has more privacy. Your <u>email</u> and <u>phone number</u> can be found on a site that you shared your resume, your <u>last name</u> can be found in your social media account, but it is unlikely that your <u>mother's maiden name</u> can be found on any sites. That is why it is the most sensitive one.