Marie Received a Puzzle That Has Three Pegs as a Present

Multiple Choice

Marie received a puzzle that has three pegs as a present for her birthday. To solve the puzzle, a person is required to move nine disks from the center peg to one of the outside pegs. However, only one disk can be moved at a time, and a larger disk can never be placed on top of a smaller disk. Marie's puzzle is an example of a(n)

A) problem of transformation.
B) problem of arrangement.
C) problem of inducing structure.
D) ill-defined problem.