Question

irving berlin, who wrote the song \white christmas,\ was a composer who
only wrote christmas songs.
was also a novelist.
helped shape popular music in the 1920s.
wrote only one hit song.

Explanation:

Irving Berlin was a foundational figure in early 20th-century American popular music, creating numerous hits beyond Christmas music (like "God Bless America" and "Alexander's Ragtime Band"). He was not a novelist, had many hit songs, and his work was pivotal in shaping 1920s popular music.

Answer:

helped shape popular music in the 1920s.