I say none of them. I use FRESH garlic and chop it nicely (use a garlic press or a blender). Then grab some pellets and add a bit of water. Let it soak for a few days and allow it to dry up. Now your pellets have EXTREME garlic flavor and smell and there's also a few garlic pieces they will eat for added benefit!
Just my homemade recipe, always works and a lot cheaper !!!!