This can be figured out by basic English with the usage of suffixes and language translation.
"Archaea" is another term for "archaebacteria".
"Cyanobacteria" belongs to the domain "bacteria".
"Methanogens" are bacterium that produce methane. This organism belongs to the domain "archaea".
With this information, we can conclude that answer choice "A.) Cyanobacteria" is not included in the domain "archaea".
I hope this helps!
