Which program is used to reload the defined rules for detecting and installing new devices on Linux?

The correct answer, udevadm, is a command-line utility that interacts with the udev device manager in Linux systems. udev is responsible for managing device nodes in the /dev directory and dynamically creating or removing device files as hardware is added or removed from the system. When new hardware is detected, udev uses predefined rules to determine how to handle the device.

The udevadm command specifically allows an administrator to trigger udev events, which effectively reloads the rules that dictate how devices should be managed. This capability is crucial for ensuring that the system properly recognizes and configures devices according to the latest settings specified in its configuration files.

Other options like systemctl and service are primarily used for managing system services and not for device management. Dpkg is used for handling packages in Debian-based distributions and does not pertain to device detection or management. Therefore, udevadm stands out as the correct choice for reloading device rules in Linux.