“What . . . . . . . . wonderful day!” said the tourist. A. a B. an C. the D. no article

The correct answer is D. no article.

The sentence “What a wonderful day!” is an exclamation, which means that it is expressing strong feeling. In English, exclamations do not usually take articles.

The other options are incorrect because they are all articles. Articles are words that are used to specify the identity of a noun. In the sentence “What a wonderful day!”, the noun is “day”. The speaker is not specifying which day they are talking about, so they do not need to use an article.

Here are some more examples of exclamations that do not take articles:

• What a beautiful sunset!
• What a terrible accident!
• What a surprise!