The isotope $^{222}_{86}\text{Rn}$ undergoes a decay chain, through a series of emissions, to produce the isotope $^{206}_{82}\text{Pb}$. At each step in the decay chain, either an $\alpha$-particle or a $\beta$-particle is emitted. What is the number of stages in the decay chain?
- A4
- B8
- C16
- D20