Which statement concerning electromagnetic radiation is correct?
- AWaves of wavelength $5 \times 10^{-9}\,\text{m}$ are high-energy gamma rays.
- BWaves of wavelength $3 \times 10^{-8}\,\text{m}$ are ultra-violet waves.
- CWaves of wavelength $5 \times 10^{-7}\,\text{m}$ are infra-red waves.
- DWaves of wavelength $9 \times 10^{-7}\,\text{m}$ are light waves.