user: Question: Which driver was in All rounds as an entrant of Motor Racing Developments?
Columns: ['Entrant', 'Constructor', 'Chassis', 'Engine', 'Tyre', 'Driver', 'Rounds']
Types: ['text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Motor Racing Developments', 'Brabham - Ford', 'BT33 BT34 BT37', 'Ford Cosworth DFV 3.0 V8', 'G', 'Graham Hill', 'All']
SQL:

assistant: SELECT "Driver" FROM "Table" WHERE "Rounds" = 'All' AND "Entrant" = 'Motor Racing Developments';