user: Question: What is Opponent, when High Rebounds is "Pierson (6)"?
Columns: ['Game', 'Date', 'Opponent', 'Score', 'High points', 'High rebounds', 'High assists', 'Location/Attendance', 'Record']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [30.0, 'September 5', 'Indiana', '90-68', 'Pierson (20)', 'Pierson (6)', 'McWilliams-Franklin , Pierson (4)', 'Palace of Auburn Hills 9,287', '18-12']
SQL:

assistant: SELECT "Opponent" FROM "Table" WHERE "High rebounds" = 'Pierson (6)';