But now the focus has changed and ________ huge leisure industry has developed around it.

• A. A
• B. The
• C. An
• D. Some

Answer: (A)

Introducing a non-specific, singular count noun requires an indefinite article. Here, we’re presenting a new idea—“a huge leisure industry” around it—so an indefinite article is needed. Use a because the word starts with a consonant sound, while an would be used before vowel sounds. The, meanwhile, would point to something already known or defined, which isn’t the case here, and some isn’t used for a singular count noun in this context.