Clearly,
$P\ \square \ Q \equiv Q\rightarrow P \equiv Q' \vee P$
according to the given truth table.
A. $Q' \ \square \ P' \ \equiv \ P' \rightarrow Q' \equiv (P')' \vee Q' \equiv P \vee Q'$
B. $P \ \square \ Q' \ \equiv \ Q' \rightarrow P \equiv (Q')' \vee P \equiv {\color{Green} {Q \vee P}}$
C. $P' \ \square \ Q \ \equiv \ Q \rightarrow P' \equiv Q' \vee P'$
D. $P' \ \square \ Q' \ \equiv \ Q' \rightarrow P' \equiv (Q')' \vee P' \equiv Q \vee P'$
So, Option (B) is correct.