Can I target dx10 rather than dx11 for geometry shaders?

I know unity supports direct x 9, and direct x 11, but I’m hoping to have access to geometry shaders (introduced with dx 10) in unity without requiring dx 11 as, according to steam hardware stats, plenty of users still have hardware which only supports dx 10.

The question is, if I use geometry shaders, am I restricting my game to dx 11 only, or can I target dx 10 to support a broader user base?

Any clarity here would be greatly appreciated.

Thanks.

In case anyone is interested in the answer. I believe you cannot explicitly target dx10 in a shader. However, if you target dx11, but only use dx10 features, people with dx10 hardware and dx11 installed will be able to run your game. If you use any dx11 features, at that point you will be excluding people with dx10 hardware.

Hope that helps.