The Windows Server DHCP role supports reservations that map a client's unique identifier (commonly the MAC address) to a specific IPv4 address inside the scope. The AZ-800 study material describes reservations as the mechanism to "ensure that a particular device always receives the same IP address from the DHCP server while still being managed by DHCP." When a reservation exists, the DHCP server will always offer and lease the reserved address to that client and will not allocate that address to any other client. This meets scenarios such as networked printers, appliances, or servers that require a consistent IP but where you still want centralized lease management (lease tracking, option delivery, and centralized auditing). The content further contrasts reservations with exclusions and options: exclusions remove addresses from the pool and options deliver configuration parameters, neither of which guarantees a stable assignment to a given device.
Therefore, creating one DHCP reservation per printer in Scope1 precisely satisfies the requirement that the printers are always assigned the same IP address.