Final answer:
The most plausible film according to NASA scientists was 'Gattaca' (1997).
Step-by-step explanation:
The 1997 film starring Ethan Hawke and Uma Thurman that was considered the most plausible by NASA scientists at the conference in 2011 was Gattaca. It is a science fiction film set in a future where genetic engineering has become common, and the story revolves around genetic discrimination and the possibility of a person overcoming their genetically predetermined limitations.