${ }^{234}\text{ Th (III B) }$emits particles such that new element is in II A. Particles emitted one can be

• A

  one $\mathrm{\alpha }$, one $\mathrm{\beta }$

• B

  one $\mathrm{\beta }$, one $\mathrm{\alpha }$

• C

  only one $\mathrm{\beta }$

• D

  only one $\mathrm{\alpha }$