  Charm mesons produced in nucleus-nucleus collisions are expected to be less
attenuated (quenched) by the medium than hadrons containing only light quarks,
since radiative energy loss of heavy quarks should be reduced by the
`dead-cone' effect. We start from a published energy-loss model to derive the
quenching for D mesons at the LHC, introducing an approximation of the
dead-cone effect and employing a Glauber-based description of the geometry of
central Pb-Pb collisions to estimate the in-medium path lengths of c quarks. We
show that the exclusive reconstruction of D^0 \to K\pi decays in ALICE allows
to measure the nuclear modification factor of the D mesons transverse momentum
distribution and the D/(charged hadrons) ratio and, thus, to investigate the
energy loss of c quarks.
