Biconditional statements – UGC NET Question

Statements A, B, C and E correctly state the truth conditions and logical role of biconditionals, while D is false. “If and only if” requires that p and q share the same truth value, which can be expressed as two conditionals taken together. It is false exactly when one is true and the other false. Far from being only sufficient, p is both necessary and sufficient for q in a biconditional, so D misdescribes the relation. Recognising this helps with equivalence transformations in UGC NET questions.

Option A:
Option A is incomplete because it omits E, not mentioning how biconditionals feature in exam-style equivalence problems. A, B, C only therefore leaves out a key application of the concept.

Option B:
Option B is wrong since it drops A, thereby failing to state in general that biconditionals are true when p and q match in truth value. B, C, E only provides specific and exam-related facts but lacks the core truth-condition statement.

Option C:
Option C is correct as it gathers all the true statements and excludes D, which restricts the relation to sufficiency alone. This option aligns with standard propositional logic and how biconditionals are tested in symbolic reasoning questions.

Option D:
Option D is incorrect because it omits B, losing the important equivalence of a biconditional with two conditionals. A, C, E only is therefore not acceptable as the right answer.