Anatomy deals with the internal structure of living organisms, but it is not focused on the study of cells.
Cytology refers to the study of cells, but it is a narrower term that does not directly emphasize the structural and functional aspects as a unit of life.
Morphology refers to the study of the form and structure of organisms, not specifically the cellular level of function and structure.
Cell Biology is the correct term because it specifically focuses on the study of cells as structural and functional units in living organisms.
Thus, the correct answer is Cell Biology.