PDFs of key physical properties of H II regions and of GMCs. Top, from left to right: Extinction-corrected Hα luminosity and size. Bottom, from top left to bottom right: CO luminosity, size, peak temperature, velocity dispersion, surface density, characteristic turbulent linewidth, free-fall time, and virial parameter. The distribution for the full GMC (H II region) population is shown in red, while the matched GMCs–H II regions adopting a MOP of 10, 40, and 70% are shown in blue, green, and gold, respectively.