I use the Windows version of Rhino at work but am trying out the Mac version at home. My Windows version of Rhino is running on Parallels (I know, it is not ideal, but have only had one crash in months of working this way). In the Windows version, when selecting multiple objects, if an object is accidentally selected it can be deselected by clicking on it with the Control key (then hold shift and continue adding to selection). This is not the case in the Mac version. Clicking with the Control key brings up a menu displaying other features. Then I thought I’d try clicking the object with the Option key… everything deselected.
Am I missing something? I am not a veteran 3D modeler and have only been using Rhino for a few months. So maybe it is my inexperience.