Choosing the right API Level for my android application

Question

I currently have a application targeted at android 2.3 (api level 10), but went thinking that probably people using android 2.1/2.2 or older won\'t even be able to see

Answer 1

If you have

then it will appear right down to 1.6, but make sure you don't use antyhing that they don't have in their API

edit: Don't bother with 3! :)