D). showing readers that Montag is mentally unstable.
Explanation:
The indirect characterization in the given excerpt displays that Montag has been badly conditioned by his dystopian society. His odd reaction on Clarisse's serious remarks on the firemen during their conversation reveals this conditioning and lack of social skills in him. The shallow and weird response from him <u>gives a hint of mental insatbility and psychosomatic illness which was a product of his society's prohibition and restriction on him for enjoying the joys of nature</u>. Thus, <u>option D</u> is the correct answer.
