How is personal information defined in relation to identifying characteristics of a person?

The correct choice highlights that personal information is specifically defined as information that can be retrieved by personal identifiers. Personal identifiers include data such as names, social security numbers, and other unique attributes that allow one to specifically identify an individual. This definition is critical in various legal contexts, including privacy laws and regulations governing how personal information is used or disclosed.

By focusing on the aspect of retrieval through identifiers, this choice emphasizes the operational aspect of personal information. It underlines the importance of recognizing how certain pieces of data can be categorized as "personal" based on their ability to connect to an individual uniquely.

The other options address different aspects of the concept but do not accurately encapsulate the regulatory and legal definition of personal information. For instance, simply stating information can be "legally accessed" does not define personal information in the context of its identifying characteristics. Similarly, actions done to a person or beliefs and preferences may contribute to understanding an individual but do not strictly define their personal information as it pertains to identifiable characteristics. Therefore, the correct answer effectively encapsulates the legal understanding of personal information and its identification.