Loading XAML graphics dynamically

Hi,
I've got a lot of XAML (vector) graphic elements.
I would like 1 graphic to be loaded dynamically, according to conditions met in the program.
In clear, I would like "GraphA" to be displayed if user has chosen "A", "GraphB" displayed if user has chosen "B"...etc

My question is:
How can I get those XAML elements saved in a library, or resource, as it is possible for bitmap and sounds for instance. Preventing them to be downloaded, but included in the project.
And then, how can I load 1 graphic in a canvas, and replace it by another (in the same canvas) according to users choice?

Thanks a lot for your help!