Which of the following must be included in all patient records?

The inclusion of essential identifying information in patient records is critical for both legal and clinical reasons. Full name, date of birth, social security number, and gender provide a comprehensive demographic profile that is necessary for accurate patient identification and for the fulfillment of various legal and administrative requirements in healthcare.

Full name ensures that the patient's identity is clearly linked to their medical records, which helps to avoid confusion with other patients. The date of birth not only serves to confirm identity but is also critical in assessing age-related health risks and eligibility for certain treatments. The social security number is often used for billing and insurance purposes, while gender can be relevant for specific health assessments, treatment protocols, and statistical tracking.

Other options may include important aspects of patient care or preferences but do not encompass the minimum necessary legal information required for all patient records, thereby making them insufficient when compared to the requirements outlined in the correct answer.