Explanation:

- The sentence involves the incorrect use of tense, "is being made," which suggests an ongoing action, not suitable for a historical figure like Antonio Stradivari.

- Option 1: who made wonderful

- This is correct. It uses the simple past tense, appropriate for describing the actions of a person in history.

- Option 2: who have made wonderful

- This is incorrect. "Have made" is in the present perfect tense, implying the action continues to the present, which doesn't fit when discussing someone from the past.

- Option 3: who is made wonderful

- This is incorrect. It suggests the violins themselves are made wonderful by someone else.

- Option 4: who makes wonderful

- This is incorrect. This present tense does not suit a historical context for someone who lived in the past.

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