C is the best answer. It is a component of the cell theory which states that all living things are composed of one or more cells.
The word cell comes from the Latin word "cella" which means small room. The cell is the basic unit of life, the basic unit of all living things. All organisms are made of one or more cells, from bacteria and amoeba which consist of as few as one cell to the human body which is made of as many as a trillion cells.
Cells are critical to the study of life and are usually referred to as the building blocks of life. All cells contain the following:
1. Lipid bilayer boundary called the plasma membrane.
2. Cytoplasm
3. DNA
4. Ribosomes for the synthesis of protein.
