Top : $\pt$-differential cross section for prompt $\Dzero$, $\Dplus$, and $\Dstar$ mesons in pp collisions at $\sqrts=2.76 $TeV compared with the scaling of the ALICE measurement at $\sqrts=7 $TeV. Bottom : Ratio of the $\sqrts=2.76 $TeV cross section and the $\sqrts=7 $TeV measurement scaling, where the filled boxes represent the scaling uncertainties and the empty boxes the measurement systematics.