6537. He has always been an elusive customer.

✅ The correct answer is option A.
Ambiguous : open to more than one interpretation; not having one obvious meaning.

Unreliable : not able to be relied upon.

Deceitful : guilty of or involving deceit; deceiving or misleading others.

Quarrelsome : given to or characterized by quarrelling.

Elusive : difficult to find, catch, or achieve.

Synonym of Elusive is Ambiguous