Answer:
Pueden hacer la tarea.
Step-by-step explanation:
Pueden descagar musica means that you are able to download music. Pueden instalar juegos means that you are able to install games. Pueden comunicarse con mensajes instantaneos means that you are able to communicate with instant messages. None of these things you are able to do on a school computer. Therefore, your answer would be the first one.
Hope this helps! :)