In which of the following is customer access blocked and alert disabled?

The correct choice is maintenance mode. During maintenance mode, a system or application is temporarily taken offline to perform necessary updates, repairs, or improvements. As a result, customer access is intentionally blocked to ensure that no external interactions interfere with the maintenance process. This enhances security and stability by preventing unauthorized access and changes during critical operations.

Moreover, alert notifications are typically disabled during this period to avoid unnecessary alerts that could arise from downtime or system changes, allowing maintenance personnel to focus on the task at hand without being distracted by alerts indicating that users are unable to access the system.

In contrast, hosted VMs, public cloud, and hybrid cloud scenarios generally do not involve a complete blocking of customer access or the disabling of alerts as part of their normal operation. Hosted VMs may allow for customer access unless they are specifically taken down for maintenance or further tasks. Public and hybrid clouds provide services designed for accessibility and uptime, making maintenance processes more complex and usually ensuring that alerting mechanisms remain active to inform stakeholders of any issues that may arise during services available to customers.