Please help me understand this question.

[nuzzle]

I got it.

As I indicated, the recursive function can be simplified and then it becomes even clearer how it works,

void ReadListBackward(node* p) {
   if (!p) {
	printf("T!\n"); // recursion terminates
   } else {
	printf("F: %d\n", p->data); // print in forward direction
	ReadListBackward(p->next); // recursive call
	printf("B: %d\n", p->data); // print in backward direction
   }
}