All of the following are tested by the T.O. CONFIG button except:

The T.O. CONFIG button is designed to check various parameters and configurations of the aircraft before takeoff to ensure safe operation. When the T.O. CONFIG button is pressed, it evaluates several critical systems and indicators to verify that the aircraft is properly configured for departure.

The option regarding CAB PR LO DIFF PR is correct because this particular check relates to the cabin pressure differential, which is not specifically monitored by the T.O. CONFIG button. Instead, the button primarily focuses on essential aircraft configurations required for takeoff, such as the settings for slats and flaps, the status of doors, and brake temperatures.

Checks related to slats, doors, and brake temperatures are vital for ensuring that the aircraft can safely take off. Slats and flaps must be in the correct configuration, doors need to be securely closed, and brake temperatures must be within acceptable limits to prevent issues during takeoff. Thus, while the T.O. CONFIG button verifies those items, cabin pressure differential monitoring is part of a larger system of checks not encompassed by this specific pre-takeoff configuration assessment.