In the top of the maple tree, the sparrow was busy building nest. which pronoun correctly completes the sentence? a) its b) his c) she d) their

The speaker, an indian who feels lonely during a trip to England, meets with one of his childhood friends, whose name is Aaron. Aaron worked in a pub located in the city of London; the speaker and him met after the former learned about Aaron's whereabouts after a call with his own mother. Aaron died of cancer at one point in the story.