Which of the following statements most closely summarizes the central idea of the following passage (paragraph 10)?

Whitman’s personal beliefs most closely resembled Transcendentalism and he was well versed in the work of Emerson, but he also had a broad understanding of American and European religious traditions, language, and symbolism, which he used stylistically in his poetry. He employed traditional symbols such as the stars, moon, and earth, but also created his own symbology, which included lilacs, the calamus plant, and, of course, grass. Whitman’s tone was exuberant and his diction, or word choice, is notable for its eccentricities; he used colloquial words, foreign words, technical words, and sometimes even made up his own words.
a
Walt Whitman was one of the first artists to popularize the ideas of Romanticism and Transcendentalism in Europe.
b
Walt Whitman’s work was a direct rejection of popular movements within Romanticism, as he believed that they oppressed artists’ natural expression.
c
Walt Whitman was a revolutionary American poet who embodied the characteristics of the Romantic movements through his work.
d
Walt Whitman’s work was very different from other poets of the time and he enjoyed experimenting with language in unusual ways.