Ratios of production cross sections as a function of $\pt$ of prompt $\Dplus/\Dzero$, $\Dstar/\Dzero$, $\Ds/\Dzero$, $\Ds/\Dplus$, and $\Ds/(\Dzero+\Dplus)$ mesons in pp collisions at $\s = 5.02$ TeV , $\s = 7$ TeV , and $\s = 13$ TeV. Vertical bars (boxes) report the statistical (systematic) uncertainties.