Final answer:
The internal control principle being exemplified in this scenario is establishing responsibility.
Step-by-step explanation:
The internal control principle being exemplified in this scenario is a) establishing responsibility. Each cash drawer being assigned to only one employee ensures that they are accountable for the contents and can be held responsible for any discrepancies or mismanagement. This helps to prevent confusion, reduce the risk of theft or errors, and promote transparency in the supermarket's financial transactions.