What Nucleus Decays by Beta Emission to Produce Antimony-121?
A) ${ }_{50}^{120} \mathrm{Sn}$

What nucleus decays by beta emission to produce antimony-121?

A) ${ }_{50}^{120} \mathrm{Sn}$
B) ${ }_{51}^{122} \mathrm{Sb}$
C) ${ }_{50}^{121} \mathrm{Sn}$
D) ${ }_{52}^{121} \mathrm{Te}$
E) ${ }_{53}^{125} \mathrm{D}$