Valid and fallacious conditional forms – UGC NET Question

Statements A and B describe modus ponens and modus tollens, which are valid forms, while C and D describe affirming the consequent and denying the antecedent, which are invalid. E correctly classifies A, B vs C, D in exam terms, and F restates that only A and B among the four are correct patterns. Thus A, B, E and F are true, whereas C and D are false as descriptions of valid forms. This makes A, B, E and F only the correct combination.

Option A:
Option A is incomplete because it omits F, which explicitly summarises that only A and B (among A–D) are valid patterns.

Option B:
Option B is wrong since it includes C, thereby treating affirming the consequent as if it yielded a valid inference.

Option C:
Option C is correct because it includes all true statements (A, B, E, F) and excludes the false ones (C, D).

Option D:
Option D is incorrect as it omits A (modus ponens), which is one of the key valid forms.