Which of the following is a venue of communication specific to a subgroup?

The correct choice is a term known as "argot," which refers specifically to the specialized language or vocabulary used by a particular group or subgroup, often to communicate in a way that is not easily understood by outsiders. This type of communication is typically employed to establish identity or camaraderie among members of the group, while simultaneously allowing them to maintain a degree of secrecy from those outside the subgroup.

In contrast, standard language refers to a form of language that is widely accepted and understood across a broader population, lacking the exclusivity that argot has. Colloquialisms are informal expressions or phrases commonly used within a particular region or community but do not necessarily reflect a specialized vocabulary unique to a subgroup. Common vernacular, while inclusive and rooted in everyday language, generally describes the language patterns used by the general public rather than a specific subgroup's unique mode of communication. Thus, argot is distinctively associated with preparing and utilizing a specific linguistic framework for a defined subset, making it the most appropriate answer in the context of this question.