The answer is: all of the above.
In "The Kite Runner," dying Rahim Khan asks Amir to return to Pakistan to see him. There, Amir finds out that his childhood friend Hassan and his wife have been killed by the Talibans, and that Hassan is actually his half-brother. Rahim also tells him that Hassan has a son, Sohrab who is in an orphanage in Kabul.
