Answer: The use of ammonia as a refrigerant is a problem because it is toxic.
Step-by-step explanation:
The use of ammonia as a refrigerant is a problem because it is toxic.
Ammonia may cause severe burns and migrates to moist areas of the body like skin, eyes, nose, throat etc due to its hygroscopic nature.
Ammonia has a much broader explosive range as it is toxic in nature.
so, use of ammonia in refrigerator is a problem.
Hence, Third option is correct.