¿_________ tú un viaje en tren? translates to "[blank] you a train trip?" The options are as follows.
a. Hicimos - "We did"
b. Hiciste - "You did" (informal)
c. Hicieron - "They did"
d. Hizo - "He/She did" or "You did" (formal)
The subject is tú, which is the informal "you" in Spanish. The correct answer is hiciste.
¿Hiciste tú un viaje en tren? - "Did you make a trip by train?"
