Final answer:
Amir refers to his birthday gifts as "blood money" because they symbolize his guilt and serve as a form of atonement for betraying his friend Hassan. The term illustrates his perception of the gifts as tainted and the depth of his internal moral struggle.
Step-by-step explanation:
Amir calls his birthday gifts "blood money" because he feels a profound sense of guilt and perceives the gifts as a tainted form of compensation for his wrongdoing. This term usually refers to money paid in compensation for a wrongful death or injury, but Amir uses it metaphorically to express his moral conflict. The term "blood money" implies that the gifts are a form of atonement for the figurative 'blood' on Amir's hands, stemming from his betrayal of his friend Hassan. This inner turmoil leads him to view the gifts as a hollow attempt to ease his conscience, hence the designation of them being "blood money."
The internal struggles of characters and the moral dilemmas they face often lead them to ascribe deeper meanings to material possessions, as demonstrated by the conflicted feelings attached to the birthday gifts. Amir's perception of the gifts reflects his emotional state and serves as a manifestation of his ongoing struggle with his sense of wrongdoing and desire for redemption. The weight of this guilt and the desire to be 'cleansed' or forgiven plays into the broader themes of the narrative, emphasizing the complexities of human psychology and morality.