Which of the following quantities is dimensionless?

Which of the following is dimensionless?

The dimensional formula for $r.m.s.$ (root mean square) velocity is

Dimensions of kinetic energy are

Write the $CGS$ and $MKS$ units of the universal gravitational constant $G$. Also,write the dimensional formula of $G$.

Given below are two statements :
Statement $(I)$ : Dimensions of specific heat are $\left[L^2 \,T^{-2} \,K^{-1}\right]$.
Statement $(II)$ : Dimensions of gas constant are $\left[ML^2 \,T^{-1} \,K^{-1}\right]$.