The correct answer is D. no article.
Ice is a solid form of water. It is formed when water freezes at or below 0 degrees Celsius (32 degrees Fahrenheit). Ice is a common substance on Earth, and it can be found in many different forms, such as snow, icicles, and glaciers.
The article "a" is used before singular nouns that refer to a specific person, place, thing, or idea. The article "an" is used before singular nouns that begin with a vowel sound. The article "the" is used before singular nouns that refer to a specific person, place, thing, or idea that has already been mentioned or that is unique.
In the sentence "Ice is frozen water," the word "ice" is a common noun that refers to a general type of substance. Therefore, no article is needed.
