At how many metres must pedestrians' reflective elements be visible?

At how many metres must pedestrians' reflective elements be visible?
A)At 150 metres.Correct
B)At 100 metres.
C)At 50 metres.
Pedestrians travelling on interurban roads, between sunset and sunrise or under conditions that reduce visibility, must wear a luminous or reflective element that is visible at a minimum distance of 150m.