Definition of sound argument – UGC NET Question

A sound argument is defined as a valid argument with all true premises. Because of validity, the conclusion logically follows from the premises. Because the premises are true, the conclusion must also be true in reality. Thus the description in the stem corresponds exactly to the notion of a sound argument.

Option A:
Option A, strong, usually refers to inductive arguments in which the premises make the conclusion highly probable. Strength does not guarantee truth with necessity and need not involve validity. Therefore strong is not the correct technical term here.

Option B:
Option B correctly names a sound argument as one that is valid with true premises. Such arguments provide the highest level of logical assurance about their conclusions. Hence sound is the most appropriate choice for the situation described.

Option C:
Option C, cogent, also describes a good inductive argument with strong support and true premises. However, cogency belongs to inductive, not strictly valid deductive, reasoning. Thus cogent does not match the definition given in the stem.

Option D:
Option D, invalid, refers to an argument whose conclusion does not follow necessarily from its premises. In an invalid argument, true premises may still lead to a false conclusion. Therefore invalid is the opposite of what is described and cannot be correct.