The 3rd option
Mi hermano (My brother)
A los estudiantes no les gusta la tarea.
A ti y a mi nos interesa el arte
A ella le aburre el fútbol
A ti no te falta nada
The answer is A. Tú tocas el piano. Because Tu tocas is the only correct way of saying you are playing the piano in this instance. C is saying "tocan" which is wrong because it's saying you but then using a the group form of playing. The same thing with B, it's also using the group form of playing and it's past tense. And D is using the I form of playing not the you form.
D. Sepas
Hope that helped
El jugo de naranja - The orange juice
Debes beberlo frío - you must drink it cold
Ponlo en la ensalada - put it on the salad
Debes comerla con una cuchara - you must use a spoon to eat it.
