Which of the following is NOT considered personal data?

Personal data refers to any information that relates to an identified or identifiable individual. The correct answer, which is a company registration number, is not considered personal data because it pertains to a business entity rather than an individual. Company registration numbers are used for the identification of companies in official registries and do not provide any direct information about a person's identity.

In contrast, a name, medical information, and a postal address all relate to individuals and can be used to identify them. Personal data protection laws, such as GDPR, specifically focus on safeguarding the privacy of individual information, making the distinction between personal data and non-personal data crucial in the context of data protection and privacy legislation.