Your question is really vague, but when I typed it in, I found this website with people answering the same question: https://studyandanswers.com/biology/question20660094
Domain Archaea
Like bacteria,Organisms in domain Archaea are prokaryotic and unicellular. Superficially, they look a lot like bacteria, and many biologists confused them as bacteria until a few decades ago.
Answer:
Option A
Explanation:
Only an autotrophic species can convert methane into food.
Deep below the sea, methane and hydrogen sulfide are found in abundance. These gases get mixed into the sea water.
Autotrophic bacteria containing phosynthetic pigments oxidize these dissolved gases thereby producing food.
Hence these autotrophic bacteria’s will be considered as producers as they produce food.
Thus, option A is correct.