  The recent measurements of $R_{K^+}$, $R_{K_S^0}$, $R_{K^{*+}}$,
$B_s\to\mu^+\mu^-$, a set of CP-averaged angular observables for the $B^0\to
K^{*0}\mu^+\mu^-$ decay, and its isospin partner $B^+\to K^{*+}\mu^+\mu^-$ by
the LHCb Collaboration, consistently hint at lepton universality violation in
the $b\to s\ell\ell$ transitions. In this work, we first perform global fits to
the $b\to s\ell\ell$ data and show that five one-dimensional scenarios, i.e,
$\delta C_9^{\mu}$, $\delta C_{10}^{\mu}$, $\delta C_L^{\mu}$, $\delta
C_9^{\mu}=C_{10}^{\mu\prime}$, and $\delta C_9^{\mu}=-C_9^{\mu\prime}$ can best
explain the so-called B anamolies. Furthermore, we explore how these scenarios
can be distinguished from each other. For this purpose, we first study the
combinations of four angular asymmetries $A_i$~$(i=3,4,5,9)$ and find that they
cannot distinguish the five new physics scenarios. We then show that a newly
constructed ratio $R_{S}$ can uniquely discriminate the five new physics
scenarios in proper intervals of $q^2$ if it can be measured with a percent
level precision.
