Concept:An unpaid seller has specific rights against the buyer, but cannot declare the buyer bankrupt.
Explanation:After the sale of goods, the unpaid seller may keep possession of the goods until payment is made.
The seller can also stop the goods while they are in transit if the buyer becomes insolvent.
Additionally, the seller may resell the goods under certain conditions.
However, the right to declare a defaulting buyer bankrupt is not granted to an unpaid seller.
Bankruptcy proceedings are a legal matter handled by courts, not by the seller.
Answer:A. declaring the buyer bankrupt.