Applying Masks in Flash Allows for the Creation of Depth

Applying masks in Flash allows for the creation of depth on the Web page. Which of the following is true when creating vector masks?

A) A mask layer contains a filled shape that blocks off objects on at least one other layer.
B) You create masks on motion guide layers and normal layers in Flash.
C) You can link no more than one layer to a single mask layer.
D) Creating a mask requires an understanding of action scripting.