What happens in the phase coming in between G${}_1$ and G${}_2$ phase?

The correct option is B DNA replication
Interphase has the longest duration in the cell cycle and during this phase the cell prepares to divide by undergoing cell growth and DNA replication.
Interphase is further divided into $G_1$, S and $G_2$ phases. The phase coming in between $G_1$ and $G_2$ phase is S phase. During S phase, DNA replication occurs.

Karyokinesis is division of nucleus and cytokinesis is division of cytoplasm and they occur post $G_2$ phase.