El año pasado yo
a Maine de vacaciones.

Answer Choices
Fuiste
Voy
Vas
Fui

The correct answer would be "Fui"

Explanation:

For this question you have to use the correct term for the first person "yo", voy is conjugated in the "yo" form, however the sentence has to be in the past tense, therefore fui is the right option.

Fui

Explanation:

El año pasado means last year, so we have to pick a choice in the past tense.

Voy and vas are in the present tense, so they are not correct.

Fui and fuiste are both in the past tense. The sentence uses yo, so fui must be the correct choice.

El año pasado yo fui a Maine de vacaciones.

Translation: Last year, I went to Maine on vacation.