Given the rationale, provide a reasonable question and answer. Step-by-step reasoning process: If a confrmation is denied, the confirmation fails. When a refrence deny the confirmation, it means they do not know that person which fails the confirmation.
 The question and answer:
An attempt to confirm an applicant's reference would fail if the reference does what?
Options:
- question
- dispute
- deny
- contradict
- refuse
The answer is deny