Final answer:
The Work center supervisor is responsible for verifying and signing the Tag-Out Guide List (4790/107) to ensure safety during maintenance operations.
Step-by-step explanation:
The person responsible for verifying and signing the Tag-Out Guide List (4790/107) before it can be used is a. the Work center supervisor. The Work center supervisor's verification ensures that all safety and procedural checks are in place for maintenance activities. This validation process is critical for maintaining safety and preventing potential hazards or accidents during equipment maintenance and operations within a military or industrial environment.