Which of the following is correct for adders?

$($A$)$ Full adders have the capability of directly adding decimal numbers

$($B$)$ Full adders are used to make half adders

$($C$)$ Full adders are limited to two inputs

$($D$)$ In a binary adder, the first stage may be a half adder

An $8-$bit register may provide storage for two's$-$complement codes within which decimal range?

$($A$)-128+127$

$($B$)-127+128$

$($C$)-127+127$

$($D$)0099$

An $8-$bit register may provide storage for $BCD$ codes within which decimal range?

$($A$)-128+127$

$($B$)-127+128$

$($C$)-127+127$

$($D$)0099$

What is the decimal value of $"11100",$ when interpreted as a two's$-$complement signed number?

$($A$)20($B$)-12($C$)-4($D$)12$

What is the decimal value of $"11100",$ when interpreted as a signed$-$magnitude number?

$($A$)20($B$)-12($C$)-4($D$)12$