Answer:
D
Explanation:It’s Riemann negation
Mercedes va al parque de atracciones con sus hijos un dia al mes , cada año. Ella va a veces .
The name already suggests that the "personal" a is needed for people - So we will choose an option that has a person with its object. (so not with "reglas" )
It's not needed for possession, so it will not appear with the sentences that have "tener" in them.
It is needed in the last option: mira a Pablo.
Also, we will need it for "dile al encargado" because the encargado is a person in charge. But then it will bind with "el" forming "al" - so not "a" anymore
