Step 1: const int arr[5] = {1, 2, 3, 4, 5}; The constant variable arr is declared as an integer array and initialized to arr[0] = 1, arr[1] = 2, arr[2] = 3, arr[3] = 4, arr[4] = 5 Step 2: printf("Before modification arr[3] = %d", arr[3]); It prints the value of arr[3] (ie. 4). Step 3: fun(&arr[3]); The memory location of the arr[3] is passed to fun() and arr[3] value is modified to 10. A const variable can be indirectly modified by a pointer. Step 4: printf("After modification arr[3] = %d", arr[3]); It prints the value of arr[3] (ie. 10). Hence the output of the program is Before modification arr[3] = 4 After modification arr[3] = 10