Comparison of the Hubble Space Telescope optical image (left panel) with the ALMA high-resolution cube of GAMA 526784 (middle). The star clusters (which are expected to be embedded in GMCs) are marked with labels corresponding to their numbers, following the naming convention used in Paper I. The beam size and orientation are indicated by the white ellipse in the bottom-left corner of the middle panel. Right: Spectra of the four brightest clusters, with the expected CO(1 − 0) emission wavelength marked in red. No detectable CO(1 − 0) emission is observed in any of the spectra.