¿Quiénes investigan el precio de los boletos? = Who checked the price of the tickets?
then your options are
Grandparents
Parents
Children
And I do not know the translation for the last one, check if you messed up a character and let me know please!
Answer:
Trabajan
Explanation:
For indicativo presente, the correct conjugation of trabajar for ellos/ellas is trabajan.
Good luck!
