Single-celled and complex multicellular organisms have evolved different mechanisms to maintain life...

Single-celled and complex multicellular organisms have evolved different mechanisms to maintain life processes. Which of the following best compares how a single-celled amoeba and a multicellular human remove waste?
A) Both the amoeba and the human rely solely on the respiratory system to expel all metabolic byproducts into the environment.
B) Only the multicellular human needs to remove waste; single-celled organisms do not have to remove waste.
C) The amoeba removes waste through contractile vacuoles and the cell membrane, while the human uses organ systems with specialized organs (like the excretory and circulatory systems) to remove waste.
D) The amoeba uses specialized organs like kidneys to filter blood, while the human relies on simple diffusion across the cell membrane.