Not possible to determine a consumption account

I have created a sales order with item category TAB (Indiv.Purchase Order)
But I'm getting the error 06 138 (Not possible to determine a consumption account). And now I have to setup automatic posting for this transaction.
I know that the transaction key is GBB, but can someone please tell me witch "general posting key" and "valuation class" I should use for this purpose. I think that the valuation class should be 3100 but I'm not sure.

Answer:
1.
Check out the schedule line category in transaction VOV6 to see what account assignment category should be used in MM.

2.
Check out the account assignment category in Customizing (Materials Management - Purchasing - Account assignment - Maintain account assignment categories) to see what account modification key should be used.

3.
The valuation class is fetched from the material master - accounting view of the involved material.