Which of the following Boolean expressions is not a tautology? [JEE Main 2021, 22 Jul (Shift 2)]

(a) \((~p\Rightarrow q)∨(~q\Rightarrow p)\)

\( (\sim(\sim p) \vee q) \vee(\sim(\sim q) \vee p) \)
\( \equiv(p \vee q) \vee(q \vee p) \)
\( \equiv p \vee q \vee q \vee p \)
\( \equiv p \vee q\)

(b) \((q\Rightarrow p)∨(~q\Rightarrow p)\)

\( (\sim q \vee p) \vee(\sim(\sim q) \vee p) \)

\( \equiv(\sim q \vee p) \vee(q \vee p) \)
\( \equiv \sim q \vee p \vee q \vee p \)
\( \equiv(\sim q \vee q) \vee(p \vee p) \)
\( \equiv \text { True } \vee p \)
\( \equiv \text { True }\)

(c) \((p\Rightarrow ~q)∨(~q\Rightarrow p)\)

\( (\sim p \vee \sim q) \vee(\sim(\sim q) \vee p) \)
\( \equiv(\sim p \vee \sim q) \vee(q \vee p) \)
\( \equiv \sim p \vee \sim q \vee q \vee p \)
\( \equiv(\sim p \vee p) \vee(\sim q \vee q) \)
\( \equiv \text { True } \vee \text { True } \)
\( \equiv \text { True }\)

(d) \((p\Rightarrow q)∨(~q\Rightarrow p)\)

\( (\sim p \vee q) \vee(\sim(\sim q) \vee p) \)
\( \equiv(\sim p \vee q) \vee(q \vee p) \)
\( \equiv \sim p \vee q \vee q \vee p \)
\( \equiv(\sim p \vee p) \vee(q \vee q) \)
\( \equiv \text { True } \vee q \)
\( \equiv \text { True }\)