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

### Instruction:
What is the region 1 where region 4 is tba is the complete eighth series?

### Inputs:
table_name: table, columns: ['Complete Series', 'Region 1', 'Region 2', 'Region 4', 'DVD Extras and Bonus Features', 'Number Of Discs']

### Response:
SELECT Region 1 FROM table WHERE Region 4 = TBA AND Complete Series = The Complete Eighth Series