若有以下程序: #include <iostream> using namespace std; class sample private: int x; public: sample() void setx(int i) x=i; friend int fun(sample B[],int n) int m=O; for (int i=O; i<n; i++) if(B[i].x>m) m=B [i].x; return m; ; int main ( ) sample A[10]; int arr[]=90,87,42,78,97,84,60,55,78,65; for (int i=O;i<10;i++) A[i]. setx (arr[i]); cout<<fun(A, 10)<<end1; return 0; 该程序运行后的输出结果是( )。
A. 97
B. 84
C. 90
D. 78