The interviewers need assurance that you are ready and willing to meet their ethical standards. They'll study your choice of words, body language, and nonverbal cues to determine the sincerity of your answer. Non-verbal cues that indicate when a person is being dishonest are fidgeting with your hands, leaning back, repeating the question to stall for time, and looking away, to name a few. Exhibit integrity. Display your ability to navigate the nuance of such uncomfortable situations with emotional maturity. This question is a character test.
From their Core Values; "Integrity and Authenticity: Seek truth. Be intellectually and interpersonally honest with others. Make ethical decisions. Personal and Professional Accountability: Be mission-focused. Honor and follow through on commitments and agreements made to others. Work collaboratively as a team member. Be reflective and transparent in communications with others. Always provide your best effort in work performance. Speak up when professional or ethical standards are being violated."