Consider the following C code. Which outputs are possible?

int main() {
  printf("A");
  if (fork() == 0) {
    usleep(((rand() % 5) + 1) * 10000); /* wait for a random time */
    printf("B");
    if (fork() == 0) {
      usleep(((rand() % 5) + 1) * 10000); /* wait for a random time */
      printf("C");
    }
    else {
      wait(NULL);
      printf("D");
    }
  }
  else {
    usleep(((rand() % 5) + 1) * 10000); /* wait for a random time */
    printf("E");
    wait(NULL);
  }
  return 0;
}