Final answer:
Archaea are more closely related to Eukaryotes than any other monophyletic group due to shared traits between Archaea and Eukarya that Bacteria do not possess.
Step-by-step explanation:
Archaea are more closely related to Eukaryotes than to any other monophyletic group. While Bacteria and Archaea are both prokaryotes, scientists have found that Archaea share several traits with Eukarya that Bacteria do not share. This suggests that Eukarya arose when an Archaean cell fused with a Bacterial cell, becoming the nucleus and cytoplasm of a new Eukaryan cell, which is why Archaea are more closely related to Eukaryotes.