Barium-137 Emits a Gamma Ray in the Decay from an Excited

Barium-137 emits a gamma ray in the decay from an excited state (¹³⁷Ba^*) . What is the resulting daughter nuclide?

A) (¹³⁷Cs)
B) ( ¹³⁷Ba)
C) ( ¹³⁷La)
D) ( ¹³⁶Ba)
E) (¹³⁶Cs)