Answer:
a. Full-adders have a carry input capability.
Explanation: Adders are used in the Computer and other digital devices to execute the tasks of numbers addition,in a computer system it is usually part of the arithmetic logic unit, which uses logic to add numbers.
Adders can either be a full-adder or a half-adder,A full-adder consists of three inputs and two outputs while the half-adder has two inputs and two outputs.