The correct answer is: D. no article
The house on the right belongs to my uncle. In this sentence, the house is not specific, so we do not need to use an article. We can use the article “the” when we are talking about a specific house, such as “The house on the corner is for sale.” However, in this sentence, we are not talking about a specific house, so we do not need to use the article “the.”
The article “a” is used when we are talking about a general house, such as “I want to buy a house.” However, in this sentence, we are not talking about a general house, we are talking about a specific house that belongs to my uncle.
The article “an” is used before singular nouns that begin with a vowel sound, such as “an apple.” However, in this sentence, the noun “house” does not begin with a vowel sound, so we do not need to use the article “an.”
Therefore, the correct answer is: D. no article