Which of the following is considered a confidential data element?

• A. Email address
• B. Public phone number
• C. Office location
• D. Social Security number

Answer: (D)

Protecting data elements that can cause serious harm if disclosed is the focus here. A Social Security number is a highly confidential identifier because it uniquely ties to a person and can be used to commit identity theft across multiple systems, from financial to medical records. Because of that risk, it requires strict handling: minimal collection, restricted access, and strong protections like encryption both at rest and in transit. In comparison, an email address is personal but often publicly available or broadly used for contact, so it’s not treated with the same level of secrecy. A public phone number is intended to be public, and an office location is typically information that can be shared with clients or visitors in many contexts. So, the element that necessitates the strongest confidentiality controls is the Social Security number.