Explanation:

- "Classic" generally refers to something that is traditional, typical, or standard and is exemplary in form or recognized as the best of its kind.

- Option 1: Traditional - This is a synonym of "classic," as both suggest enduring practices or styles.

- Option 2: Expensive - This describes cost and does not serve as an antonym to "classic."

- Option 3: Atypical - This means not representative of a type, group, or class. It's an antonym because it denotes something not usual or not conforming to the generally expected form.

- Option 4: Usual - This refers to something commonly occurring or typical, similar to "classic."