whEn thE DEmAnD For FACiAl tissuEs inCrEAsED, ______.
A．thE supply wAs quiCkly ExhAustED
B．its priCE wEnt up
C．thE mAnuFACturErs triED to improvE its quAlity
D．morE mAnuFACturErs wEnt into thE BusinEss oF mAking tissuEs