user: Question: What is the election with an outcome of NDC opposition and 2,728,241 votes?
Columns: ['Election', 'Candidate', 'Number of votes', 'Share of votes', 'Outcome of election']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['2012', 'John Dramani Mahama', '5,574,761', '50.7%', 'Mahama NDC government']
SQL:

assistant: SELECT "Election" FROM "Table" WHERE "Outcome of election" = 'NDC opposition' AND "Number of votes" = '2,728,241';