Which indicates pre-order traversal?

A. Left sub-tree, Right sub-tree and root B. Right sub-tree, Left sub-tree and root C. Root, Left sub-tree, Right sub-tree D. Right sub-tree, root, Left sub-tree

A queue is a ?

 a) FIFO (First In First Out) list  b) LIFO (Last In First Out) list. c) Ordered array d) Linear tree