Which device can be used to perform binary addition?

An adder is the device specifically designed for performing binary addition. It takes two binary numbers as inputs and produces a sum as an output, alongside a carry output if the addition exceeds the binary representation capacity of the bits being used. Adders can be implemented in various forms, such as half adders and full adders, depending on whether they handle carry inputs. The half adder adds two single binary digits and outputs the sum and carry, while the full adder adds three binary digits (two significant bits and a carry from a previous addition).

Comparators, multiplexers, and decoders serve entirely different purposes. Comparators are used to determine the relational value between two binary numbers, such as checking if one number is greater than, less than, or equal to another. Multiplexers select one of several input signals and forward the selected input into a single line, primarily used in data routing. Decoders convert binary information from 'n' input lines to a maximum of 2^n unique output lines, effectively used for selecting specific outputs based on the binary input but are not involved in arithmetic operations like addition. Therefore, the adder stands out as the correct choice for binary addition in digital electronics.