A radioactive source $S$ produces $\alpha$-particles, $\beta$-particles and $\gamma$-rays. A detector is positioned $5\ \text{cm}$ from $S$. A thin sheet of paper is inserted as shown in the diagram. Which emissions from the source are able to be detected?
- A$\alpha$-particles and $\beta$-particles only
- B$\alpha$-particles and $\gamma$-rays only
- C$\beta$-particles and $\gamma$-rays only
- D$\alpha$-particles, $\beta$-particles and $\gamma$-rays