That would be productivity.
It was the year 1798 that Thomas Malthus predicted that the humanity would be met with mass starvation. His prediction was based on an assumption that human population would far exceed the means of producing food and that we just would not be able to produce enough food for everyone. But the technological advancement and the advanced farming techniques allowed us to increase productivity and thus avert this prediction.
The answer is B all four planes were travelling long distances
