Which of the following composers is associated with the use of tone clusters?

The composer who is associated with the use of tone clusters is Henry Cowell. Tone clusters are defined as groups of adjacent notes that are played simultaneously, creating a dense and complex harmonic texture. Cowell was one of the early 20th-century composers who explored this innovative technique, employing it to expand the expressive potential of music. His works often incorporate unconventional striking methods on the piano, allowing for the production of rich, sonorous textures that challenge traditional harmonic concepts.

In contrast, the other composers listed, like Johann Sebastian Bach, Claude Debussy, and Antonín Dvořák, are known for their distinct musical styles that do not primarily include tone clusters. Bach focused on counterpoint and harmony typical of the Baroque period, Debussy explored impressionistic qualities with rich tonal palettes but did not typically use tone clusters in the way Cowell did, and Dvořák is celebrated for his melodic and symphonic contributions that reflect Czech folk music traditions. Cowell's pioneering approach to modern composition sets him apart as the one closely associated with tone clusters.