【单选题】

From the last three paragraphs we know that ______.
A．lengthening the existing 53-kilometer subway is among the 50 large projects

B．the length of the subway will be up to 135.25 kilometers in 2005
C．a 40.5-meter-long line will be added to Beijing's first light railway
D．a 70-meter-wide green belt will supply us with enough water