Problem analysis: Definition of an axisymmetric figure: If a figure is folded along a straight line, the parts on both sides of the straight line can overlap each other, and this figure is called an axisymmetric figure.

As can be seen from the figure, the axisymmetric figure is the first, second and fourth type, so B is selected.

Comments: This problem belongs to the basic application problem, and it can only be completed if students master the definition of axisymmetric graphics skillfully.