Answer:
The correct answer is the third option Cell.
Explanation:
The smallest functional unit of biological structure that fulfills the functional requirements of living in the cell. Cells are "building units of life".
The study of cells is termed as cellular biology or cell biology. Cells made up of cytoplasm covered by a membrane, which contains many biomolecules and cell organelle such as nucleic acids and proteins nucleus, endoplasmic reticulum and other.
Thus, the correct answer is the cell.
