It's Panama (and it's borders are Colombia[South America], Costa Rica, Caribbean Sea, and the Pacific Ocean).
Costa Rica is the narrow country that curves from the west to the east in Central America. It is situated between Nicaragua to the north and Panama to the south.
Panama.
Panama is a narrow country in Central America that curves from west to east. It is the southern most county in North America connecting it to South America via Colombia.
Panama
The only central American country that starts with an 'e' is El Salvador. This should narrow your options.
the narrow county that curves from the west to the east is Panama and its borders are Costa Rica and Colombia.
An isthmus is a narrow strip of land that connects to larger land areas. The Central American country of Panama is an isthmus that connects the southern portion of North America with the continent of South America.
Panama
Panama
Panama.
a toboggan
Pretty much all Central American countries are on an isthmus, but you probably want Panama.