Answer:
d) Himself
Step-by-step explanation:
Arnold Schoenberg (1874–1951), an influential Austrian-American composer, is renowned for pioneering the twelve-tone technique, a revolutionary approach to composition that shaped 20th-century music.
In his early years, Schoenberg was largely self-taught with informal guidance from friends and fellow musicians. His only formal music teacher was Alexander von Zemlinsky (1871 - 1942) under whom he studied composition from around 1894.