Histograms of three progenitor parameters: M_ZAMS (top panel), M_ej (middle panel), and R (bottom panel). The gold sample is represented by yellow bars, and the red bars are the histograms for the full sample. In each panel, the number of SNe II is listed, together with the median and the 16th and 84th percentiles. Probability density functions of the physical parameters for the gold and full samples are represented by solid and dashed lines, respectively.