user: Question: what is the quantity made when the class is D-2?
Columns: ['Class', 'Wheel arrangement', 'Fleet number(s)', 'Manufacturer', 'Serial numbers', 'Year made', 'Quantity made', 'Quantity preserved']
Types: ['text', 'text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['2-6-2 — oOOO — Mogul', '2-6-2 — oOOO — Mogul', '2-6-2 — oOOO — Mogul', '2-6-2 — oOOO — Mogul', '2-6-2 — oOOO — Mogul', '2-6-2 — oOOO — Mogul', '2-6-2 — oOOO — Mogul', '2-6-2 — oOOO — Mogul']
SQL:

assistant: SELECT "Quantity made" FROM "Table" WHERE "Class" = 'D-2';