How do you change the crop bounding box to portrait format from landscape format?

To access full screen mode in Lightroom:

What is the keyboard shortcut for Library grid view?

When mapping your photos, you need not be online.

What keyboard shortcut cycles forward / backward through Lightroom's lights out modes?

Which of the following Library module controls are only available from the loupe view?

How do you change the crop bounding box to portrait format from landscape format?

Which of the following is NOT one of the 4 choices you can select when choosing how fast larger previews will appear when you zoom in on one once it's in Lightroom?

Lightroom Edits photos via: