UGC NET Questions (Paper – 1)

Modus ponens is the classic valid form that affirms the antecedent of a conditional. It states that if “if p, then q” is true and p is true, then q must also be true. This structure preserves truth from premises to conclusion. Therefore the argument form described in the stem is called modus ponens.

Option A:
Option A correctly names modus ponens as the rule that moves from “if p then q” and “p” to “q”. It is one of the most frequently used inference forms in deductive reasoning. Hence this option is the correct answer.

Option B:
Option B, modus tollens, involves denying the consequent by arguing from “if p then q” and “not q” to “not p”. This is a different but also valid pattern. Thus modus tollens does not match the form given here.

Option C:
Option C, disjunctive syllogism, reasons from a disjunction and the denial of one disjunct to the affirmation of the other. It uses “either…or” rather than a conditional premise. Therefore it is not the pattern described in the stem.

Option D:
Option D, hypothetical fallacy, is not a standard name for any recognised valid form. It vaguely suggests an error rather than a rule of inference. Consequently hypothetical fallacy is not an acceptable answer.

Modus tollens is a valid form of argument that denies the antecedent by denying the consequent of a conditional. It proceeds from “if p, then q” and “not q” to the conclusion “not p”. This preserves truth because if p were true, q could not be false. Therefore the pattern described in the stem is known as modus tollens.

Option A:
Option A, affirming the consequent, argues from “if p then q” and “q” to “p”. This pattern is invalid because q might be true for other reasons. Thus affirming the consequent is a fallacy, not the valid form in the question.

Option B:
Option B correctly names modus tollens as the rule that infers “not p” from “if p then q” and “not q”. It is a central tool in deductive proof and refutation. Hence this option accurately answers the question.

Option C:
Option C, denying the antecedent, moves from “if p then q” and “not p” to “not q”. This is also invalid because q could still be true for other causes. Therefore denying the antecedent cannot be the form intended by the stem.

Option D:
Option D, reductio error, is not a standard label for this precise conditional pattern. While reductio arguments sometimes use similar ideas, the technical name of the form in the question is modus tollens.