Answer:
The correct answer is a. domain Eukarya.
Step-by-step explanation:
Bacteria archaea and eukarya are considered as the three domains of life. Bacteria and eukarya lack a membrane-bound nucleus and other membrane bound organelle therefore they are considered in prokaryotes and organisms having membrane-bound nucleus comes under domain eukarya.
So the organism which have eukaryotic cell comes under domain eukarya. These organisms can be single cellular or multicellular and their genetic material is packed in a double membranous structure called the nucleus. So the correct answer is a. Eukarya.