Need to amend my return to show loss from business (Schedule C, 1040). What do I select in order to do that?

You will need to upgrade to the Self Employed version to fill out schedule C expenses to show a loss.

How to amend a 2016 Online return      
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You will amend the return and if you didn't enter a Sch C on the original return you will need to upgrade to the Self Employment version first to open the Business tab ...

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