The correct answer is D. no article.
The word “garden” is a common noun, which means it refers to a general class of things. In this case, the garden is not a specific garden, but rather any garden that is near the speaker’s house. Therefore, we do not need to use an article.
If we were to use an article, it would imply that we are talking about a specific garden. For example, if we said “Let’s sit in the garden near my house,” we would be implying that there is only one garden near the speaker’s house, and that we are talking about that specific garden.
However, in this case, we are not talking about a specific garden. We are simply saying that we want to sit in a garden that is near the speaker’s house. Therefore, we do not need to use an article.