Answer:
Caminar en la arena de la playa
Comer mariscos
Explanation: Here we need to choose the right answers to:
"What things can you do on the beaches of El Salvador?"
-Nadar en un piscina de agua de mar
"Swim in a pool of seawater."
This does not have a lot of sense, so we can discard it.
-Caminar en la arena de la playa
"Walk in the sand of the beach"
This is a right answer, you can do it.
-Comer mariscos
"Eat seafood"
This is another thing you can do there, is common to see some restaurants right next to the beach.
-Explorar un cráter
"Explore a crater"
While is true that there is a crater in El Salvador, the crater is not located on a beach.