Radioactive source S gives out $\alpha$-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 radiations 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