The correct answer is D. no article.
The article "a" or "an" is used before singular nouns that refer to a general or indefinite person, place, thing, or idea. The article "the" is used before singular nouns that refer to a specific or definite person, place, thing, or idea.
In the sentence "My cousin is now a student at Michigan University," the noun "Michigan University" is a specific place, so the article "the" is not used.
The other options are incorrect because they are all articles.
