user: Question: What opponent has a Result of W 31–0?
Columns: ['Week', 'Date', 'Opponent', 'Result', 'Attendance']
Types: ['real', 'text', 'text', 'text', 'real']
Sample row: [1.0, 'September 18, 1977', 'Kansas City Chiefs', 'W 21–17', 58185.0]
SQL:

assistant: SELECT "Opponent" FROM "Table" WHERE "Result" = 'W 31–0';