The correct answer is D. Chamber concerto
Step-by-step explanation:
Dumbarton Oaks or Concerto in E- flat is a type fo chamber concert, this means, as other chamber concerts this includes popular dance forms and a suite (set of band pieces). Additionally, this was written by the Russian composer Igor Stravinsky in 1937 and integrated the participation of multiple instruments such as violin, clarinet, bassoons, cellos, etc. that included in total fifteen players that played all the piece during around 20 minutes. According to this, it can be concluded Stravisnksy's Dumbarton Oaks is a chamber concerto.