Which is the smallest Panorama solution that can be used to manage up to 2500...

The smallest Panorama solution that can be used to manage up to 2500 Palo Alto Networks Next Generation firewalls is the M-200 appliance.

The M-200 is designed for medium-sized organizations and provides the necessary performance and scalability to manage a large number of firewalls efficiently.

The M-600 is a more powerful appliance but is not the smallest option.

The M-100 has been superseded by the M-200 and does not support as many devices.

The Panorama VM-Series can manage a large number of devices but is not typically considered the "smallest" solution due to its virtual nature and varying performance based on the underlying hardware.