The opposite of "pauciloquy" (the practice of speaking little) is "loquacity" (the quality of talking a lot). Thus, "loquacity" is the correct antonym.
- Tatter refers to something torn or in poor condition.
- Tactile relates to touch, not related to speaking.
- Concomitance means accompanying or happening together, unrelated to speech.
Thus, the correct answer is "loquacity".