Identify which internal control concept is being violated and explain how this may cause an opportunity for fraud to occur within a business:
1. The supervisor for the purchasing department has not taken a vacation in three years.
2. Inventory Is left in a receiving area at the back of the store by an open door.
3. The purchasing supervisor has the authority to order a purchase and also to receive the merchandise, record its receipt, and authorize the accounting department to issue a check.