Answer: Bolivia and Paraguay
Step-by-step explanation:
A landlocked country is a country surrounded by land or lacking access to the sea or the ocean, and in South America there are two countries that have this characteristic: Bolivia and Paraguay.
This is considered a geographical disadvantage, as these countries must incur higher transportation costs in import and export, compared to other countries in the region. In addition, this fact separates these countries from the wealth and commercial activities that occur on the sea coast, such as fishing and maritime trade.
It should be noted that Bolivia previously had coastline and access to the Pacific Ocean, but lost this privilege in the Pacific War, which confronted it, along with Peru, with Chile.