In which domain(s) are single-celled organisms found? A. Bacteria and Eukarya B. Archaea and Eukarya C. Only Archaea D. Bacteria, Archaea, and Eukarya

the correct answer is b

The single-celled organisms are found in Archaea and Eukarya. The Eukarya believed to be originated from Archaea. Eukarya contains a membrane - bound nucleus while the archea has no nuclear membrane. The answer is B. I hope my answer helps you.