Answer: 4th option: Juan come tacos ayer.
Explanation:
El tiempo cambió: The weather changed.
Ayer cuide a mi sobrina: Yesterday I took care of my niece.
Ellos limpiaron su casa: They cleaned their house.
Juan come tacos ayer: Juan eats tacos yesterday. ==> Uses wrong verb tense. Supposed to be 'Juan ate tacos yesterday'(Juan comió tacos ayer).
Hence, it's the 4th option.
