Answer:
Domain- or subject-specific words inform the reader that the author is writing about a particular topic (third option).
Step-by-step explanation:
Domain- or subject- specific words are words or terms that belong to a particular subject or category, like, Math terminology, or literature-specific words. If you see the word 'metaphor,' the text is likely about the analysis of a particular novel or story.
Option 1 is not correct because those words might be completely new to the reader.
Option 2 is not correct because subject-specific words cannot be applied to any subject because they are specific to only one.
Option 4 is not correct because the author isn't necessarily an expert in a specific field only because he/she uses special terminology.