user: Question: Who was the opponent at the week 4 game?
Columns: ['Week', 'Date', 'Opponent', 'Result', 'Game site', 'Record', 'Attendance']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'real']
Sample row: [1.0, 'September 3, 1966', 'at Houston Oilers', 'L 7–45', 'Rice Stadium', '0–1', 30156.0]
SQL:

assistant: SELECT "Opponent" FROM "Table" WHERE "Week" = 4.0;