What country is an isthmus linking central and south america? honduras guatemala panama puerto rico?

The country that is an isthmus linking Central and South America is Panama.

Explanation:

Panama is a country located in the southeast of Central America. Its official name is Republic of Panama and its capital is Panama City. It borders on the north with the Caribbean Sea, on the south with the Pacific Ocean, on the east with Colombia and on the west with Costa Rica. It has an area of 75 420 km². Located on the isthmus of the same name, a strip that joins South America with Central America, its mountainous territory is only interrupted by the Panama Canal basin, the interoceanic road that connects the Atlantic Ocean with the Pacific Ocean.