To control access to sensitive data at the field level, the system administrator should use Column Level Encryption (CLE).

Here's how CLE works:

Field-Level Encryption: CLE allows you to encrypt specific fields within a table, ensuring that only authorized users with the necessary decryption keys can access the data.

Granular Control: You can define different encryption keys for different fields or groups of fields, providing fine-grained control over data access.

Role-Based Access: You can grant access to decryption keys based on user roles, ensuring that only authorized personnel can view sensitive information.

Why not the other options?

A. PI1 Encryption: This is not a standard ServiceNow encryption feature.

C. Cloud Encryption: This is a broader term for encryption solutions provided by cloud providers, not a specific ServiceNow feature.

D. Full Disk Encryption (FDE): This encrypts the entire hard drive, not individual fields within the application.