The diffusion of innovations model categorizes adopters into five established categories: innovators, early adopters, early majority, late majority, and laggards. While "progressive" isn't a standard category within the model, it could be interpreted as encompassing the early adopters and early majority who are more forward-thinking in adopting new practices. Given the provided options and answer key, selecting all four (A, B, C, and D) appears to be the intended response. However, it's important to recognize that the inclusion of "progressive" is non-standard.