user: Question: Who was the opponent at the League Cup competition with a score of 3-1?
Columns: ['Date', 'Competition', 'Opponents', 'Venue', 'Score']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['29 September 1971', 'European Cup Winners Cup', 'SC Dynamo Berlin', 'Home', '4-5']
SQL:

assistant: SELECT "Opponents" FROM "Table" WHERE "Competition" = 'League Cup' AND "Score" = '3-1';