对于一个头指针为head的带头（哨兵)结点的单链表，判定其后链表为空的条件是______

A.head==NULL

B.head→next==NULL

C.head→next==head

D.head!=NULL

A.head == NULL

B.head == NULL

C.head -＞ prior == head

D.head -＞ next == head

A.head==NULL

B.head-＞next=NULL

C.head-＞next==head

D.head!=NULL

A.head!=NULL

B.head-＞next==head

C.head==NULL

D.head-＞next==NULL

A.head-＞next==NULL

B.head!=NULL

C.head-＞next!=NULL

D.head==NULL

A.this.head.next==null;

B.this.head==null;

C.this.head.next==this.head;

D.this.head!=null;

A.head—＞next= =NUL

B.head= =NULL

C.head—＞next= =head

D.head!=NULL

A.head-＞next==NULL

B.head==NULL

C.head-＞next==head

D.head!=NULL

A.head-＞next==NULL

B.head==NULL

C.head-＞next==head

D.head!=NULL

A.head = = NULL;

B.head-＞next = = NULL;

C.head-＞next = = head;

D.head! = NULL;