The diagram illustrates the tracks taken by three different forms of radiation X, Y and Z. Which row correctly names X, Y and Z?
- AX: $\alpha$-particles; Y: $\beta$-particles; Z: $\gamma$-rays
- BX: $\beta$-particles; Y: $\alpha$-particles; Z: $\gamma$-rays
- CX: $\beta$-particles; Y: $\gamma$-rays; Z: $\alpha$-particles
- DX: $\gamma$-rays; Y: $\alpha$-particles; Z: $\beta$-particles