Bike helmet supporters claim that helmets reduce the risk of severe injury, citing studies that compare medical outcomes of those who crash with and without a helmet. However, those critical of bike helmets argue that while the rate of severe injury decreases with a helmet, the likelihood of an accident increases due to factors like reduced peripheral visibility. These lines of reasoning reveal that bike safety is often not simple to define and requires more careful analysis.

Which of the following statements best expresses the main conclusion of the above argument?

A. Bike helmets reduce the risk of severe injury.
B. Bike safety is a complex issue.
C. Bike helmets obstruct peripheral vision.