user: Question: What is listed in built for when the original number is 24D?
Columns: ['GE-DL works no.', 'Year built', 'Built for', 'Original no.', 'New owner', 'New no.']
Types: ['real', 'text', 'text', 'text', 'text', 'text']
Sample row: [35261.0, '1974-75', 'Iscor', '1D', 'SAR', '34-501']
SQL:

assistant: SELECT "Built for" FROM "Table" WHERE "Original no." = '24D';