i wrote a program by using 2d array.Now i cannot understand

Question

 

 I wrote a program by using 2d array.Now i cannot understand where is the problem in this program:

#include <stdio.h>

main()

{

int i,j;

int arr[2][5]={{1,2,3,4,5},{6,7,8,9,10}};

for(i=0;i<10;i++){

int flag = 1;

if (arr[i][j] == 1) flag = 0;

{

for(j=2;j<=arr[i][j]/j;j++){

if (arr[i][j]%j == 0) {

flag = 0;

break;

}

}

if (flag)

printf("This is num:%d \n",arr[i][j]);

}

return 0;

}

}