The sentence is in the second person singular (you). Therefore, the correct pronoun is tú.
B. que es esto? is the wrong one
Answer:
yo canto
los chicos venden
tu hablas
paco y yo comemos
nosotros vivimos
mi mama abre
los maestros escriben
Explanation:
(assuming you need to conjugate in the present?)
*De repente
*Chillante
*Silencio
*Lívido
*Amagó
*Filosa
*Amenazante
*Inmovilizados
*Gotas
*Lentamente
*Terrible
*Estupefacto.