In the disintegration of a radioactive element, `alpha`- and `beta`-particles are evolved from the nucleus.
`._(0)n^(1) rarr ._(1)H^(1) + ._(-1)e^(0) +` Antineutrino + Energy
`4 ._(1)H^(1) rarr ._(2)He^(4) + 2 ._(+1)e^(0) +` Energy
Then, emission of these particles changes the nuclear configuration and results into a daughter nuclide. Emission of an `alpha`-particles results into a daughter element having atomic number lowered by 2 and mass number by 4, on the other hand, emission of a `beta`-particle yields an element having atomic number raised by 1.
A radioactive element belongs to `III B` group, it emits ona `alpha`- and `beta`-particle to form a daughter nuclide. The position of daughter nuclide will be in

Options

A. `II A`
B. `I A`
C. `II B`
D. `IVB`

Answer

A

Explanation

Group displacement law