Schoenberg's teacher was not a single individual, but his early influences, including concepts from Richard Wagner, played a role in shaping his unique musical language and departure from traditional tonality. Option c is the correct choice.
Schoenberg's teacher was Richard Wagner. Arnold Schoenberg, an influential composer of the 20th century, did not have a direct teacher-student relationship with Wagner, Brahms, Rimsky-Korsakov, or himself. Instead, his early influences included Wagner's ideas, especially the concept of the "endless melody," which had an impact on Schoenberg's early compositions.
Schoenberg later developed his atonal and twelve-tone techniques, leading to the creation of a unique musical language. While he admired Wagner, his departure from traditional tonality and exploration of new musical avenues mark his distinctive contribution to music, demonstrating a significant break from the Romantic traditions associated with Wagner (option C), Brahms, and Rimsky-Korsakov. Schoenberg's innovations laid the groundwork for the development of modern and avant-garde musical styles. Option c is the correct choice.