We flew to New York from . . . . . . . . Gatwick Airport near London. A. a B. an C. the D. no article

The correct answer is: D. no article

The reason is that “Gatwick Airport” is a proper noun, which is the name of a specific place. Proper nouns are always

Here are some other examples of proper nouns:

• The United States of America
• The
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  Eiffel Tower
• The Great Wall of China
• The Amazon River
• The Pacific Ocean

As you can see, all of these nouns are capitalized and do not take articles.

I hope this helps! Let me know if you have any other questions.