Which evidence does the author give to show that Khánh is Americanized?

a
Khánh hears the ticking of the clock.
b
Khánh shares his wife's concern for Mister Chinh.
c
Khánh briefly thinks of the Old and Lost rivers as an omen.
d
Khánh asks Mr. Huong if something is wrong with Mister Chinh.