Which Rule Is Used in the Following Inference $\frac { \mathrm { K } \cdot \mathrm { G } } { \mathrm { G } }$

Which rule is used in the following inference? $\frac { \mathrm { K } \cdot \mathrm { G } } { \mathrm { G } }$

A) Simp
B) Conj
C) Add
D) DS
E) HS