In which sequence the radioactive radiations are emitted in the following nuclear reaction? $$ \begin{array}{l} \mathrm{Z}^{\mathrm{X}^{\mathrm{A}}} \longrightarrow \mathrm{Z}+1^{\mathrm{Y}} \longrightarrow \mathrm{Z}_{-1} \mathrm{~K}^{\mathrm{A}-4} \\ \longrightarrow \mathrm{Z}-1 \mathrm{~K}^{\mathrm{A}-4} \end{array} $$

• A

  $\gamma, \alpha, \beta$
• B

  $\alpha, \beta, \gamma$
• C

  $\beta, \gamma, \alpha$
• Correct answer
  D

  $\beta, \alpha, \gamma$

Hence, the correct answer is option: 'D'.