Carlos is giving advice to his cousin about her upcoming trip. choose the logical answer to complete each sentence.

antes de abordar, siéntate en
a.
el mostrador
b.
la aduana
c.
la sala de espera

c. la sala de espera

Explanation:

Hi! The advice of Carlos to his cousin means that whenever you are planning a traveling, before getting on a plane, bus or train you must have to stay in a room specifically indicated for the passengers to wait until the time of boarding, this is the correct way to have a  successful trip with no problems.