The correct answer would be B. The first level contains two and the second level contains six holding a total of eight, the reason eight aren't just in one row is because only two fit in the first row.
Properties that define the light is a wave are
1. Speed : speed of light is 300,000 Km /s, It is most fundamenta property of light to define light is a wave
2. Reflection: Light particles or photons reflect off the particles or masses are continue to travel at the same speed.
3. colour
