Answer:
Kamau's father looked at his son with "unbelieving eyes" and trembles with fear when Kamau greeted him because Kamau's father was surprised to see his son who he thought was dead. So, sighting his son after a long time, was unbelievable and incredible.
Step-by-step explanation:
Kamau's father acted the way he acted because Karanja, the son of Njogu has reported that Kamau was dead. So the father were surprised to see the supposed dead son of his.
“THE RETURN” written by NGŨGĨ WA THIONG’O is a story about Kamau - he is a man returning home after spending many years away in prison. Kamau finally survived the Mau Mau and also survived the prison. The Mau Mau had led to the lost of many Black Nationalist’s lives, and it has resulted to many more put away in jails.