When working with the retouching tools, why would viewing your cursor as Brush Size be helpful? Where do you go to make this setting?

What will be an ideal response?

The brush size option gives a visual representation of the exact pixel area you are affecting with a particular tool. To make this setting, choose Photoshop > Preferences > Cursors (Macintosh) or Edit > Preferences > Cursors (Windows), and under painting cursors choose brush size (if not already selected).