How do I correctly set up, access, and free a multidimensional array in C?

Question

I have seen dozens of questions about “what’s wrong with my code” regarding multidimensional arrays in C. For some reason people can’t seem to wrap their head around what is

Answer 1

Going off of Jen's answer, if you want to allocate space for a 3D array, in the same manner, you can do

int(*A)[n][n] = malloc(sizeof(int[num_of_2D_arrays][n][n]));

for (size_t p = 0; p < num_of_2D_arrays; p++)
  for (size_t i = 0; i < n; i++)
    for (size_t j = 0; j < n; j++)
      A[p][i][j] = p;

for (size_t p = 0; p < num_of_2D_arrays; p++)
    printf("Outter set %lu\n", p);
    for (size_t i = 0; i < n; i++)
      for (size_t j = 0; j < n; j++)
        printf(" %d", A[p][i][j]);
      printf("\n");

free(A);