Which of the Following Is Correct for Full- Adders

Multiple Choice

Which of the following is correct for full- adders?

A) Full- adders are limited to two inputs, since there are only two binary digits.
B) Full- adders have the capability of directly adding decimal numbers.
C) Full- adders are used to make half- adders.
D) The first stage of a parallel full- adder may be a half- adder.