Consider the function f defined below.

For a given linked list p, the function f returns 1 if and only if (GATE CS 2003)

A. the list is empty or has exactly one element 

B. the elements in the list are sorted in non-decreasing order of data value 

C. the elements in the list are sorted in non-increasing order of data value 

D. not all elements in the list have the same data value.

struct item { int data; struct item next; * }; int f (struct item *p) { return ( (p = NULL) || (p->next = NULL) || (( P->data next->data) && f (p->next)) );