Which operant focuses on conversation and maintaining dialogue?

The correct choice is Intraverbal, as it specifically refers to a type of operant behavior where a person responds verbally to someone else's verbal behavior. This means that intraverbals are crucial for maintaining conversations and dialogues because they involve generating responses based on what someone else has said, often without the presence of a direct stimulus. For instance, when you ask someone a question and they provide an answer, or when they build upon your statement with additional information, they are engaging in intraverbal behavior. This aspect of verbal communication is essential for developing social skills and fostering ongoing interactions.

In terms of the other options, tact typically involves labeling or describing objects, actions, or events and may not inherently focus on dialogue or conversational skills. Receptive language refers to the understanding and comprehension of spoken language rather than the ability to engage in conversation. Expressive language, while it involves verbal output, does not specifically reference the interactional aspect of sustaining dialogue in response to another person's communication. Therefore, intraverbal is uniquely positioned to represent an operant explicitly geared toward conversation and dialogue maintenance.