The correct answer is D. Chile.
MERCOSUR is a trade bloc between Argentina, Brazil, Paraguay, and Uruguay. It was established in 1991 with the signing of the Treaty of Asunción. The goal of MERCOSUR is to create a common market between the member countries, which would allow for the free movement of goods, services, capital, and people.
Chile is not a member of MERCOSUR. However, it has a free trade agreement with the bloc. This agreement allows for the free trade of goods and services between Chile and MERCOSUR countries.
The other options are all members of MERCOSUR. Argentina is the largest country in the bloc, followed by Brazil. Paraguay and Uruguay are the smallest members of MERCOSUR.
I hope this helps! Let me know if you have any other questions.