Final answer:
The logical address of a device connected to a network or the Internet is the IP address, which is used to identify and locate the device for communication purposes.
Step-by-step explanation:
The logical address of a device connected to the network or the Internet is the IP address (a). The IP address is a unique identifier assigned to each device on a network, allowing it to be located and to communicate with other devices. The MAC address (b) is a physical address assigned to the network interface of a device and is used for local communication within the network. The subnet mask (c) is used to divide IP address space into subnetworks for organizational purposes. The DNS address (d) refers to the address of a Domain Name System server, which translates domain names into IP addresses.