When exposed to temperatures above 1000 degrees, protective systems will expand and twist, pushing out walls, and when cool, will slightly constrict.

• A. 1000 degrees
• B. 500 degrees
• C. 1500 degrees
• D. 750 degrees

Answer: (A)

The main idea is that protective devices respond to heat by expanding or moving when they reach a specific activation temperature. When the temperature climbs above that rating, the mechanism expands and can push out walls; as it cools, it will contract only slightly. The temperature value that matches this described activation point is 1000 degrees, because that is the threshold at which the system begins to respond. Lower temperatures wouldn’t trigger the action, and a higher value would indicate a different activation point than the one described.