I believe the answer is :<span> revenue streams
In business, </span><span>revenue streams refers to everything that would increase the overall income in your balance book.
Internet sales have gained massive popularity in recent years because it eliminates the cost of middleman between producer and consumer, which make the product could be sold on lower price.</span>
I would say, A, because we use it every day in our lives.
Increase in food crops = multi-level society.
Innovation and technology = non agricultural jobs
multi-level leadership = government formation
growth in resources = population growth
I'm not completely sure, but this is what makes most sense to me.
