In a radioactive decay chain, three decays occur one after another, and each one leads to the emission of a particle. The first decay leads to the emission of a $\beta$-particle. The second decay leads to the emission of an $\alpha$-particle. The third decay leads to the emission of another $\beta$-particle. Nuclides P and S are being compared. Which statement is true?
- AP and S are identical in all respects.
- BP and S are isotopes of the same element.
- CS is a different element of lower atomic number.
- DS is a different element of reduced mass.