Which microorganisms have a length equal to the free-space wavelength of an electromagnetic wave that can be seen by the human eye?
- Aalgae of length $0.5\,\mu\text{m}$
- Bbacteria of length $5.0\,\mu\text{m}$
- Cfungi of length $50\,\mu\text{m}$
- Dprotozoa of length $100\,\mu\text{m}$