When the goods are sold on credit and credit period is not expired, the seller of goods is

The correct answer is: C. Not called an unpaid seller.

An unpaid seller is a seller who has not been paid for goods that have been sold. In the case of goods sold on credit, the seller is not an unpaid seller until the credit period has expired.

Option A is incorrect because the seller is not called an unpaid seller until the credit period has expired.

Option B is incorrect because the seller is still the seller of the goods, even if the credit period has not expired.

Option D is incorrect because the seller is called an unpaid seller once the credit period has expired.