A) is close to impossible while b) is deeply in the realm of never ever not even close. Now imagine that for any number of individuals across a complex network of social connections.
People are largely a statistically predictable bag of attributes in many areas that matter for impact. The small amount of areas where humans are wildly unpredictable is what makes us beautiful and we focus on that as the "soul" of a human but they're also not usually the ones that intersect with how we care about impact.
There will be a statistical prediction of all the ways people will choose to get to a train station based on distance, weather, percentage car ownership, quality of sidewalk etc. Something as simple as improving the lighting of the right road to the train station can increase the ridership to a significant degree because it helps people feel safe walking home in the evening which means they also feel safe heading to work in the morning.
You spend enough time with a sensitive enough radar in a large organization and you see the same statistical patterns. People are milling around and impacted by their environment and things you want to make happen aren't happening until you notice the corporate equivalent of the unsafe road and you put down a couple of lights and rapid change occurs. You do it enough times consistently and you get promoted and the patterns become subtler.