Final answer:
The correct option to complete the sentence is 'un hostal'.
Step-by-step explanation:
The correct option to complete the sentence would be 'un hostal'.
In the sentence, the subject 'we' (Rentamos) rented 'una habitación' (a room) in 'Costa Rica'. The word 'hostal' is the correct option as it means 'hostel' in English.
Therefore, the complete sentence would be: 'Rentamos una habitación en un hostal en Costa Rica.'
Learn more about Completing a sentence in Spanish