user: Question: What is the date opened if thedistrict ID is 11901?
Columns: ['District name', 'Dist. ID', 'ISD', 'County', 'Authorizing agency', 'Date opened', 'Services']
Types: ['text', 'real', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Academic and Career Education Academy', 56903.0, 'Midland County ESA', 'Midland', 'Midland County ESA', '05 Sep 2006', '9-12, Alt, SpecEd']
SQL:

assistant: SELECT "Date opened" FROM "Table" WHERE "Dist. ID" = 11901.0;