Customer A with a Bronze service level package calls in a Critical System Failure at 9:00 AM. Customer B with a Silver service level package calls in a Critical System Malfunction at 10:00 AM. Customer C with a Gold service level package calls in a Critical System malfunction at 11:00 AM. Customer D with a Platinum service level package calls in a Support system malfunction at 11:30 AM. In which order should the technician visit the customers according to the priority level of their service level packages and problems?