To get tautology output of $F$ should be $1$.
option 1) $F=(x+y)+ \overline{xy}$
applying de-morgon’s law:
$F=x+y+ \bar x+\bar y$
$F=(x+\bar x)+(y+\bar y)$
$F=1 (\because x+\bar x=1) $
So option $A$ ,$\text{NAND gate}$ is correct.
we can check remaining options but none of them give $1$ as output.