I believe it's Voy, because that is the "I" or "Yo" form of the word "ir", meaning "to go".
Where are you going to eat?
(I am going to) The restaurant.
¿Adónde vas para comer?
Voy al restaurante.
Marta está poniendo el sombrero en la mesa.
The answer is Se pego because he hits his head when he felt of the ladder.
