Read the clues given below to classify an unknown organism.

Clue 1: A unicellular organism
Clue 2: Lives in the human body

What is the correct classification of the organism?
A. Domain Bacteria; Kingdom Eubacteria
B. Domain Archaea; Kingdom Eubacteria
C. Domain Bacteria; Kingdom Archaebacteria
D. Domain Archaea; Kingdom Archaebacteria