  We present the findings of a study based on a new inelastic
electron-scattering experiment on the ${}^{12}\mathrm{C}$ nucleus focusing on
the kinematic region of $Q^2=0.8\,\mathrm{GeV}^2/{c}^2$. The measured cross
section is sensitive to the transverse response function and provides a
stringent test of theoretical models, as well as of the theoretical assumptions
made in Monte-Carlo event-generator codes developed for the interpretation of
neutrino-nucleus experiments, such as DUNE and HyperK. We find that modern
generators such as GENIE and GiBUU reproduce our new experimental data within
10$\%$.
