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

### Instruction:
What is the Staffel A that has a Staffel D of Energie Cottbus and a Staffel C of Chemie Leipzig and a Staffel B of 1. FC Union Berlin?

### Inputs:
table_name: table, columns: ['Season', 'Staffel A', 'Staffel B', 'Staffel C', 'Staffel D', 'Staffel E']

### Response:
SELECT Staffel A FROM table WHERE Staffel D = energie cottbus AND Staffel C = chemie leipzig AND Staffel B = 1. fc union berlin