In terms of the hierarchical organization of life, a bacterium is ...

[Hawke]

In terms of the hierarchical organization of life, a bacterium is at the ________ level of organization, whereas a human is at the ________ level of organization.
A) single-celled organism; multicellular organism
B) single organelle; organism
C) organelle; organ system
D) single tissue; multicellular organism
E) tissue; organism

[Celeste]

(A)