Hotspot questions (standard and freeform) are multiple choice questions, which means there can only be one correct answer. Green indicates the correct hotspot, and red indicates an incorrect hotspot.
If you want a multiple-response question (that is, one that has more than one correct answer), you can create a Freeform Pick Many question.
Note: In a Freeform Pick Many, you can still use hotspots. You'll need to use Form View to indicate which hotspots are correct. However, they will all stay green. (Pick Many questions can "pick" any objects on the slide, so they aren't programmed to change incorrect hotspots to red.)
