Answer:
With the Deben
Step-by-step explanation:
The Deben was a measure of weight in copper, the Deben itself was worthless it couldn't be sold or bought, so for example everything was compared to how much it was worth in Debens, so if a kg of wheat was worth 1 Deben and a donkey was worth 15 debens, then 15 kg of wheat would be worth a Donkey, so 15 kg of wheat would be a fair trade for a donkey. Cause its worth in Debens were similar, they were fairly traded, so Debens were never involved in the transaction but it was the generally used measure for worth.