Choice "D" is correct. The Sales Article does not provide for punitive damages.
Choice "a" is incorrect. The Sales Article allows an aggrieved buyer specific performance when substitute goods cannot be purchased; e.g., where the subject matter is unique.
Choice "c" is incorrect. "Cover" (purchase of substitute goods) is one of the basic remedies available to the buyer where a seller refuses to deliver goods. Choice "b" is incorrect. Where goods have been identified (and the buyer has paid part of the purchase price), the buyer may take possession of the goods through replevin.