The word "vibrant" probably means ______.

A．8450 feet long
B．more than 8450 feet with approaches excluded
C．more than 8450 feet with approaches included
D．8450 feet long with approaches included

A．Human's future could be depended on advance in medical science.
B．We could introduce certain kind of disease to control the number of some species.
C．Human could control diseases.
D．Introduction of the myxomatosis could control rabbit population in the world.