The pseudo code below aims to reverse a linked list.

struct Node {
    int data;
    struct Node* next;
};
typedef struct Node* NPtr;

int main()
{
    NPtr head = NULL; /* Start with an empty linked list */
    push(&head, ...); /* insert items into the linked list */
    reverse(&head); /* reverse the linked list */
}

void reverse(NPtr* Href)
{
    NPtr P = NULL;
    NPtr C = *Href;
    NPtr N = NULL;

    while ( (1) ) {
        N = C->next;
        C->next = (2) ;
        P = C;
        C = N;
    }
    (3)
}

Which of the following statements are true?