Final answer:
The subject of this question is Refrigeration.
Step-by-step explanation:
Refrigeration is a process that involves cooling a space, substance, or system to lower its temperature. This is commonly used for preserving food, extending the shelf life of perishable items, and various industrial applications.
In the context of the given options, the correct answer is D) Refrigeration quiz. Refrigeration plays a vital role in modern life, impacting various aspects of our daily activities and industrial processes. Continued efforts are made to enhance efficiency and sustainability in refrigeration systems.