Note: There are 20 questions in total. Each one is 5 points. Please choose one answer for eachquestion. No extra points will be deducted for wrong answers.1. Suppose a node in a linked list A contains two fields, data and link, where link is the pointerto the following node. Let head-ptr be a pointer to the first node of A. Suppose we wouldlike to traverse all the nodes of A by the loop "while (Ihead.ptr){B；}". What is B?
(A)head. ptr == NULL；
(B) head-pr = x(head-ptr) → link；
(C) head-ptr = head-ptr -＞ link；
(D)thead ptr = x(head_ptr) → link.