The Schema Builder can be used to show the objects that are selected on the page which means that A is one of the correct answers. The other answer is C. This will also have the ability to view the page layout in a completely different window.
The schema builder is often used in order to figure out the different relationships of the items that are available with each other. It can also show the relationship only of the items that have been selected.
This is easy to use because of its drag and drop interface. Just drag some of the items with relationships that you want to check and that will prompt you to do what you are supposed to do.