How about (c) the founders of these startups were already really busy with their projects when they (barely) got around to applying? I don't know how far along

How about (c) the founders of these startups were already really busy with their projects when they (barely) got around to applying? I don't know how far along YC startups typically are when they apply, but it seems plausible that the ones that are already moving have an advantage in explaining their idea and situation.