A nuclear isotope gives out radiation that is picked up by a Geiger-Müller tube positioned about $10\ \text{cm}$ away from the radioactive source. The radiation is fully absorbed by a $2\ \text{mm}$ thick lead sheet. What can be deduced from this information about the emission from the isotope?
- AIt could be alpha and beta radiation, but not gamma radiation.
- BIt could be alpha and gamma radiation, but not beta radiation.
- CIt could be beta and gamma radiation, but not alpha radiation.
- DIt could be alpha, beta and gamma radiation.