Which term refers to the type of buying and selling that takes place within a country

a free trade

b international trade

c productivity

d domestic trade

I think the answer would be D.

"Domestic trade, also known as internal trade, is the exchange of domestic goods within the boundaries of a country."

D) Domestic trade refers buying and selling that takes place within a country.

Explanation:

Domestic trade is also otherwise home trade or internal trade and it is described as an exchange of good manufactured within the country's boundaries. There are two categories in domestic trade and they are retail or wholesale.

Wholesale trade is about buying goods in bulk from the manufacturer to distribute to smaller retailers in small quantities. Only wholesale agents' commission or wholesale merchants can perform wholesale trading. Retail trade describes selling or distributing goods in smaller packages to the consumers.