user: Question: Who was the opponent in week 4?
Columns: ['Week', 'Date', 'Opponent', 'Result', 'Record', 'Game Site', 'Attendance']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'real']
Sample row: [1.0, 'September 10, 1989', 'San Francisco 49ers', 'L 24–30', '0–1', 'Hoosier Dome', 60111.0]
SQL:

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