ACCorDing to thE pAssAgE, onE oF vErDi' s AChiEvEmEnts within thE FrAmEwork oF ninEtEEnth-CEntury opErA AnD its ConvEntions wAs to______ .
A．limit thE ExtEnt to whiCh singErs inFluEnCED thE musiCAl Composition AnD pErFormAnCE oF his opErAs
B．usE his opErAs primArily As Forums to protEst Both thE morAl Corruption AnD DogmAtiC rigiDity oF thE politiCAl lEADErs oF his timE
C．portrAy psyChologiCAlly ComplEx ChArACtErs shApED By thE politiCAl EnvironmEnt surrounDing thEm
D．inCorporAtE ElEmEnts oF FolklorE into Both thE musiC AnD plots oF his opErAs