The largest component of life among the options provided is d. Cell.
To clarify the hierarchy:
- Atoms (c) are the smallest units of matter.
- Molecules (a) are made up of atoms.
- Organelles (b) are structures within cells that perform specific functions.
- Cells (d) are the basic units of life and are larger than atoms, molecules, and organelles.
Therefore, in the context of living organisms, cells are the largest of the options listed.