Vyapti in Indian Logic refers to :

Correct answer: Invariable concomitance (अपरिवर्तनीय सहवर्तीता) Definition: Vyapti is the invariable, necessary and universal concomitance between the middle term (hetu) and the major term (sadhya) in an inference. It is the logical relation that guarantees that whenever the middle term is present, the major term is also present, enabling a valid inference. Example: Wherever there is smoke, there is fire. Here smoke (middle term) and fire (major term) show vyapti; therefore seeing smoke allows us to infer fire.

Why the other choices are incorrect: Logical contradiction (तार्किक विरोधाभास) refers to mutually incompatible statements, not to the invariable concomitance used in inference.

Direct perception (प्रत्यक्ष धारणा) is a pramāṇa meaning knowledge gained through the senses; it is not the inferential relation vyapti.

Verbal testimony (मौखिक गवाही or śabda) is a source of knowledge based on reliable verbal authority, not the invariable concomitance required for inference.