Suppose a population $A$ has $100$ observations $101,102,\dots ,200$, and another population $B$ has $100$ observations $151,152,\dots ,250$. If $V_A$ and $V_B$ represent the variances of the two populations, respectively, then $\frac{V_A}{V_B}$ is:

Variance is a measure of dispersion and is independent of the change of origin.The observations in population $B$ can be obtained by adding $50$ to each observation in population $A$ ($151=101+50$, $152=102+50$, etc.).Since $x_i(B)=x_i(A)+50$, the variance remains unchanged.
$$V_B=V_A⟹\frac{V_A}{V_B}=1$$
Both populations consist of $100$ consecutive integers, so their spread around their respective means is identical.