I will report on an ab initio calculation of the 12C elastic form factor and sum
rules of longitudinal and transverse response functions measured in inclusive (e,e')
scattering. Our calculations are based on realistic nuclear potentials and
electromagnetic currents.  The longitudinal elastic form factor and sum rule are
found to be in satisfactory agreement with available experimental data.  As I will
show, a direct comparison between theory and experiment is difficult, particularly
for the transverse sum rule.  However, it is shown that the calculated one has large
contributions from two-body currents, indicating that these mechanisms lead to a
significant enhancement of the quasi-elastic transverse response.   This fact may
have implications for the anomaly observed in recent neutrino quasi-elastic
charge-changing scattering data off 12C.   Preliminary results on the neutral
current sum rules, obtained within the same theoretical framework and presenting the
same enhancement from the two-body terms, will also be presented.