有以下程序:#include <iostream>using namespace std;class sampleprivate: int x; static int y;public: sample(int a); static void print(sample s);;sample:: sample(int a) x=a; y+=x;void sample:: print(sample s) cout<< x= <<s. x<< ,y= <<y<<end1;int sample:: y=0;int main() sample s1(10); sample s2(20); sample:: print(s2); return 0;程序运行后的输出结果是( )。
A.x=10,y=20
B.x=20,y=30
C.x=30,y=20
D.x=30,y=30