In the Boolean algebra,$(\overline {\bar A \cdot \bar B} ) \cdot A$ is equal to:

Given below are four logic gate symbols (figure). Those for $OR$,$NOR$ and $NAND$ are respectively:

The following figure $(i)$ shows a logic gate circuit with two inputs $A$ and $B$ and output $C$. The voltage waveforms of $A, B$,and $C$ are as shown in the figure $(ii)$ given below. The logic circuit gate is:

The output $D$ for the given circuit is:

Which gate is formed by the combination of gates shown below?

Which logic gate is represented by the following truth table?

$A$	$B$	$Y$
$1$	$1$	$0$
$0$	$1$	$1$
$1$	$0$	$1$
$0$	$0$	$1$