The answer you’re looking for is
D. Gamma rays
Enjoy the rest of your day/night :)
politics. Famous possible eg is of Werner Heisenberg in WW2. He delayed German attempt to build a nuclear bomb. US did build one ... hiroshima and nagasaki.
debbie may have got skilfully lucky by trial and error
Color Basics
Three Primary Colors (Ps): Red, Yellow, Blue.
Three Secondary Colors (S'): Orange, Green, Violet
Density is the mass of a substance per unit volume.