Bridgepоrt University is designing а new infоrmаtiоn system to trаck purchasing activity. The following database tables have been created.PODataPONumberPODateVendorIDPOAmountInvoiceDataInvoiceNumberInvoiceDateVendorIDInvoiceAmountPONumberPOData is the left table and InvoiceData is the right table. What join type would be used to determine if there are invoices that do not have a matching purchase order (PO)?