"The Immigration Reform and Control Act" (IRCA) for EU applicants
As far as I know, these clauses in application forms, are there for legal and nominal reasons only. The university is legally obliged by law to put this clause. This does not mean the committee will actually take this into consideration, and my experience is that they don't. 

You should thus write that you are not eligible to work currently in the US, as indeed you are not. But this should not constitute a cause for concern.