Final answer:
Levi is describing his reaction to the inmates who welcomed them to Auschwitz, realizing the dehumanizing metamorphosis that awaited them. The correct option is b.
Step-by-step explanation:
Levi is describing his reaction in the passage taken from Chapter One, "The Journey." Specifically, he is referring to b. Levi's reaction to the inmates who welcomed them to Auschwitz. This is a realization of the dehumanization and loss of personal identity that would soon befall him and his fellow prisoners.
The sense of going through a metamorphosis underscores the transformation from individuals to numbers within the concentration camp system, a future that awaited them all. Levi captures the incomprehension and madness of the situation, yet the acknowledgment of the inevitable dehumanizing process that would strip them of their humanity, much like those who had already been in the camp for some time.