Answer:
2) Hace una hora que trabajé.
Explanation:
Trabajé desde las tres hasta las cinco. Ahora son las seis.
Hace una hora que trabajé.
I worked from three to five. Now it's 6pm.
1) I have been working for two hours.
2) I have worked one hour ago.
3) I worked in a supermarket.
4) I have been working for two days.