Answer:
The correct answer would be, Focal Vocabulary.
Step-by-step explanation:
When people use specialized terms and distinctions that are specifically important to a particular or certain group, it is called as the Focal Vocabulary. This focal vocabulary makes language which contains names of things, events, ideas, etc.
So in this question, when Anil is using the vocabulary like Friending and Unfriending, it is actually describing the language of the people on social networks. So she is studying the Focal Language.