Question

what el salvadoran entity was created to secure the coffee plantations?
guardia nacional
the air force
musicas grandes
department of public works

Explanation:

Guardia Nacional was created to secure the coffee plantations. The Air Force is related to air - based military operations. Musicas Grandes is not relevant to securing plantations. The Department of Public Works is more about infrastructure and public works projects rather than securing plantations.

Answer:

Guardia Nacional