Which of the following best defines Personally Identifiable Information (PII)?

The definition of Personally Identifiable Information (PII) is best captured by the description that includes identifiers such as full names and Social Security Numbers (SSNs). PII specifically refers to any information that can be used to identify an individual uniquely. This includes direct identifiers, like names and Social Security Numbers, as well as indirect identifiers, such as demographic details, which, when combined, could allow someone to identify a person.

In contrast, options that suggest data cannot be traced back to an individual, public data, or automatically anonymized data do not fit the definition of PII. Data that cannot be traced back to an individual is not PII because it lacks the ability to identify someone. Public data available to all is also not considered PII since it can be accessed freely and does not pertain to an individual's private identifiable information. Lastly, data that is automatically anonymized is designed specifically to remove identifiers, thereby ensuring it cannot be linked back to an individual, which again disqualifies it from being classified as PII.