Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
For the year 1975, what is Propulsion, with a Number (quantity ordered) of 4756-4788 (33 buses)?

### Inputs:
table_name: table, columns: ['Make/ Model', 'Length', 'Year', 'Numbers (Quantity Ordered)', 'Fuel Propulsion', 'Year Retired']

### Response:
SELECT Fuel Propulsion FROM table WHERE Year = 1975 AND Numbers (Quantity Ordered) = 4756-4788 (33 buses)