An isotope of lead, 82212Pb^{212}_{82}\text{Pb}82212Pb, undergoes a series of radioactive decays consisting of α \alpha\,α and β−\beta^-β− emissions to form a stable isotope of lead, 82208Pb^{208}_{82}\text{Pb}82208Pb.
Which of the following decay series represents this transition?
α+β−+β−+β−\alpha + \beta^- + \beta^- + \beta^-α+β−+β−+β−
β−+α+β−\beta^- + \alpha + \beta^-β−+α+β−
α+α+β−+β−\alpha + \alpha + \beta^- + \beta^-α+α+β−+β−
α+α+β−+β−+β−+β−\alpha + \alpha + \beta^- + \beta^- + \beta^- + \beta^-α+α+β−+β−+β−+β−
