The best option that reflects the impact of Whitman's use of free verse on the themes of his poetry is:
The use of free verse allows him to use a stream of consciousness style, which gives insights into the thoughts and feelings of his characters.
Whitman's free verse encourages a more fluid and organic exploration of ideas and emotions, enabling him to delve deeply into the inner workings of the self and society without the constraints of traditional rhyme and meter. This approach enhances the themes of individuality, democracy, and the interconnectedness of all experiences in his work.