user: Question: What was the Opponent at Arrowhead Stadium?
Columns: ['Week', 'Date', 'Time', 'Opponent', 'Result', 'Game site', 'NFL Recap', 'Record']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, 'September 7, 2008', '1:15 p.m.', 'Carolina Panthers', 'L 24–26', 'Qualcomm Stadium', 'Recap', '0–1']
SQL:

assistant: SELECT "Opponent" FROM "Table" WHERE "Game site" = 'Arrowhead Stadium';