{{B}}quEstions 16 to 20 ArE BAsED on thE Following tAlk.{{/B}}

A、A、nonproFit rEsEArCh orgAnizAtion in wAshington.
B、A、tAx systEm rEsEArCh orgAnizAtion in wAshington.
C、A、sEnAtE orgAnizAtion in wAshington.
D、An EConomiC rEsEArCh orgAnizAtion in wAshington.