  We apply c-extremization, whose proof we review in full detail, to study
two-dimensional N=(0,2) superconformal field theories arising from the
low-energy dynamics of D3-branes wrapped on Riemann surfaces and M5-branes
wrapped on four-manifolds. We compute the exact central charges of these
theories using anomalies and c-extremization. In all cases we also construct
AdS_3 supergravity solutions of type IIB and eleven-dimensional supergravity,
which are holographic duals to the field theories at large N, and exactly
reproduce the central charges computed via c-extremization.
