11. In the passage, the author attributes the satisfaction of big-bands' leading musicians in part to bandleaders:
A. allowing them to exhibit their versatility by playing a different instrument during each performance.
B. placing them in small groups so they could more easily stand out from the rest of the band.
C. encouraging them to gain wider acclaim by pursuing solo opportunities outside their own bands.
D. inviting them to arrange music for their bands from time to time so they could acquire