Final answer:
The best control set for a system containing both PII and medical data is represented by Option A, which includes moderate level controls such as proximity card access, context-based authentication, UPS, and full-disk encryption.
Step-by-step explanation:
An organization is deploying a system that contains both Personal Identifiable Information (PII) and medical data and seeks to determine the best control set to protect the confidentiality of this information. Based on the control matrix provided, the moderate control level would be most applicable since it includes systems with medical data, which typically have higher security requirements than systems containing only PII. Therefore, the controls that best meet the requirements would include a combination of moderate level controls for both the physical and logical security layers.
Option A - Proximity card access to the server room, context-based authentication, Uninterruptable Power Supply (UPS), and full-disk encryption (FDE) for the database server - represents the moderate level of controls suitable for a system containing medical data. These controls provide a strong level of security for the physical server location with access limits, ensure reliability of electrical supply, and secure data at the content and application levels.