In the past ten years, there have been several improvements in mountain-climbing equipment. These improvements have made the sport both safer and more enjoyable for experienced climbers. Despite these improvements, however, the rate of mountain-climbing injuries has doubled in the past ten years.
If all of the statements above are true, which of the following, if true, best reconciles their apparent discrepancy ？（）
A．Many climbers, lulled into a false sense of security, use the new equipment to attempt climbing feats of which they are not capable.
B．Some mountain-climbing injuries are caused by unforeseeable weather conditions.
C．Mountain climbing, although a dangerous sport, does not normally result in injury to the experienced climber.
D．In the past ten years there have been improvements in mountain-climbing techniques as well as in mountain-climbing equipment.
E．Although the rate of mountain-climbing injuries has increased, the rate of mountain-climbing deaths has not changed.