Which row provides the description of $\alpha$-particles and of $\gamma$-rays?
- A$\alpha$-particles: helium nuclei; $\gamma$-rays: electromagnetic radiation
- B$\alpha$-particles: helium nuclei; $\gamma$-rays: electrons
- C$\alpha$-particles: protons; $\gamma$-rays: electromagnetic radiation
- D$\alpha$-particles: protons; $\gamma$-rays: electrons