有如下程序：
#inCluDE<iostrEAm> using nAmEspACE stD;
ClAss myClAss{&nBsp;
puBliC:&nBsp;
myClAss(int x):vAl(x){} voiD sEt(int x){vAl=x;}&nBsp;&nBsp;
&nBsp;voiD print()Const{Cout<<"vAl="<<vAl<<'\t';} privAtE:&nBsp; int vAl;&nBsp; };&nBsp;
int mAin(){&nBsp; Const myClAss oBj1(10);
myClAss oBj2(20);
oBj1.print(); //语句 1
oBj2.print(); //语句 2
oBj1.sEt(20); //语句 3
oBj2.sEt(30); //语句 4 rEturn 0;
}&nBsp; 其主函数中错误的语句是（ ）。&nBsp;
A）语句 1&nBsp;&nBsp;&nBsp; B）语句 2&nBsp;&nBsp;&nBsp;&nBsp;&nBsp;&nBsp;&nBsp;&nBsp; C）语句 3&nBsp;&nBsp;&nBsp; D）语句 4