What is the designated entrance for media members to access the facility?

The designated entrance for media members to access the facility is indeed the Main Gate, which is associated with Bldg #503. This choice is correct because it serves as the primary access point specifically allocated for media personnel, ensuring they have a controlled and designated area to enter the facility.

The Main Gate facilitates security and administrative processes essential for managing visitors, particularly those from the media, to maintain an orderly flow while adhering to security protocols. Other options may represent various locations or facilities within the broader context but do not serve the same specific function related to media access.