In the case of a $NAND$ gate,if $A$ and $B$ are the inputs and $Y$ is the output,then:

• A
  $Y=A \cdot B$
• B
  $Y=\overline{A-B}$
• C
  $Y=\overline{A+B}$
• D
  $Y=\overline{A \cdot B}$