pApEr inDustry nEEDED A nEw sourCE oF FiBEr in thE EArly 1800s is BECAusE ______.
A．pEoplE wAntED highEr quAlity pApEr
B．pApEr mADE From rAgs DEtEriorAtED too quiCkly
C．wooD pulp hAD BEComE too ExpEnsivE
D．thE supply oF rAgs wAs insuFFiCiEnt