Answer:
C. Cell, tissues, organs, organ systems
Step-by-step explanation:
Cells are the basic unit of life and also serve as a structural unit of all living beings. Many cells are together arranged into tissues to carry out specific functions. A group of tissues together make an organ while a group of organs with related functions together make an organ system.
Hence, the organization of life from simple to complex is as follows:
Cell, tissues, organs, organ systems