For this case we can translate the sentence given as:
The Salar de Uyuni _________ located in Bolivia
We must complete the sentence with the appropriate verb, that is, a verb that indicates "position or existence."
The options given are:
Es: It is the conjugation of the present tense of the verb "ser" (to be).
Está: It is a verb of state, with the meaning of being or existing in any way.
Fue: It indicates the end of "ser"
Estuve: It indicates the end of having been in a place.
Thus, the sentence is completed with option B, that is, the verb "Está"
Answer:
El Salar de Uyuni está ubicado en Bolivia