假设 head != nullptr ,下面是实现单向循环链表在头节点后插入新节点的代码,横线处应填入( )。

struct Node {
    int val;
    Node* next;
};
void insertAfterHead(Node* head, int x) {
    Node* newNode = new Node;
    newNode->val = x;
    ______________________ // 在此处填入代码
}

A.

newNode->next = head;
head->next = newNode;

B.

newNode->next = head->next;
head->next = newNode;

C.

head->next = newNode;
newNode->next = head->next;

D.

newNode->next = head->next;
head = newNode;

{{ select(1) }}

• A
• B
• C
• D