ACCorDing to thE First pArAgrAph, why puBliC oFFiCiAls AnD CAnDiDAtEs For puBliC oFFiCE routinEly usE puBliC opinion polls
A．For thE purposE oF gAining puBliC support.
B．to ovErthrow thE prEsEnt govErnmEnt.
C．to win ElECtion.
D．to know puBliC opinion.