Final answer:
The correct symbol type to use is the picture fill symbol, which allows the user to fill the polygon area with a small abstract figure of a tree.
Step-by-step explanation:
The correct symbol type to use in this scenario is the picture fill symbol. This type of symbol allows the user to fill the polygon area with a small abstract figure of a tree.
To create a picture fill symbol, the user can choose an image of a tree from their computer or from the ArcGIS library.
Once the image is selected, the user can adjust the size, rotation, transparency, and other properties of the picture fill symbol to customize the appearance of the forest area.