Read the sentences. Choose the suitable option. What you ______ here at such a late hour? You ______ your composition? - No, I (to write) it.

The first blank requires a present continuous tense to ask about an ongoing action at a specific time. The second blank requires a present perfect tense to ask about a completed action with relevance to the present. The final part indicates the action of writing, which fits the context.

Therefore, the correct option is: are you doing, Have you written.