Visible light has an approximate frequency of $5.0 \times 10^{14}\,\text{Hz}$. $M$ and $N$ are two further forms of electromagnetic radiation. The frequency of $M$ is $5.0 \times 10^{6}\,\text{Hz}$. The frequency of $N$ is $5.0 \times 10^{15}\,\text{Hz}$. What types of radiation are $M$ and $N$?
- A$M$: radio waves; $N$: infra-red
- B$M$: radio waves; $N$: ultraviolet
- C$M$: ultraviolet; $N$: X-rays
- D$M$: X-rays; $N$: infra-red