Radioactive decay follows first order kinetics and the rate constant is often termed as decay constant. Certain radioactive substance may undergo sequential decays in order to convert into a stable necleus The series comprising all such elements is termed as radioactive disintegration series.
If a radioactive disintegration series is observed involving only `alpha and beta` decays then which of the following isotopes cannot be a part of it if the parent isotope of the series is `._(91)Pa^(234)`?

Options

A. `._(86)Rn^(222)`
B. `._(85)At^(216)`
C. `._(82)Pb^(210)`
D. `._(90)Th^(230)`

Answer

B