  Using nearly 60 pb-1 of data collected with the CLEO-c detector at the
psi_prime resonance, we measure absolute branching fractions for three D0 and
two D+ Cabibbo-allowed hadronic decay modes, and the cross section for e+e- to
D Dbar at Ecm = 3.77 GeV. We report preliminary measurements of the reference
branching fractions, B(D0 to K- pi+) = (3.92\pm 0.08\pm 0.23)% and B(D+ to K-
pi+ pi+) = (9.8\pm 0.4\pm 0.8)%, and preliminary measurements of other major
branching fractions, B(D0 to K- pi+ pi0) = (14.3\pm 0.3\pm 1.0)%, B(D0 to K-
pi+ pi- pi+) = (8.1\pm 0.2\pm 0.9)%, and B(D+ to Ks pi+) = (1.61\pm 0.08\pm
0.15)%. We determine preliminary values of the cross sections, sigma(e+ e- to
D0 D0bar) = (3.47\pm 0.07\pm 0.15) nb, sigma(e+ e- to D+ D-) = (2.59\pm 0.11\pm
0.11) nb, and sigma(e+ e- to D Dbar) = (6.06\pm 0.13\pm 0.22) nb. We note that
the Monte Carlo simulations used in calculating efficiencies in this analysis
included final state radiation. However, the branching fractions used in the
Particle Data Group averages do not include this effect. If we had not included
final state radiation in our simulations, branching fractions would have been
0.5% to 2% lower.
