Final answer:
The best next step for store employees is to stop the customer, review their receipt, and deactivate the electronic article surveillance tag if necessary.
Step-by-step explanation:
The best next step for the store employees when the alarm sounds at the front of the store is to stop the customer and review their receipt to ensure they purchased the item. They should also deactivate the electronic article surveillance tag if it was not deactivated during the purchase. This step allows the employees to verify if there was a mistake or if there is a possibility of theft.