The refrigerant commonly used for domestic refrigerators is

A refrigerant is a substance used in a refrigerator to absorb heat from inside the refrigerator and release it outside, thereby keeping the interior cool.

Option A: Alcohol — Alcohol is not commonly used as a refrigerant in domestic refrigerators.

Option B: Ammonia — Ammonia can be used as a refrigerant and is widely used in industrial and commercial refrigeration systems. However, it is not commonly used in modern domestic refrigerators because of its toxicity and strong odor if leaked.

Option C: Neon — Neon is a noble gas commonly associated with lighting and is not used as a conventional refrigerant in domestic refrigerators.

Option D: None of the above — Modern domestic refrigerators commonly use refrigerants such as isobutane (R-600a). Older domestic refrigerators also commonly used R-134a.

Therefore, since alcohol, ammonia, and neon are not the commonly used refrigerants in modern domestic refrigerators, the correct answer is Option D: None of the above.