Search Tree => Can be Binary or n ary (Even B+ tree, AVL Tree are search tree only)
Heap => Can be binary as well as n ary
AVL Tree => Also a search tree, usually its binary. (didn't get any reference saying otherwise)
B Tree => Not necessarily a binary tree.
So A,B,D need not be a binary tree.
But in exam one can select D, as that maybe most appropriate "as per examiner".