“Yeah well it’s not A or B, where one is right and the other wrong. They’re both right at the same time. “
Electrons. OK.
They are not both right in your example. A in incorrect.
A is correct when the electron hits the screen. B is correct when it passes through the slits. It’s both a particle and a wave. The statistical probability of where the electron will be detected is a wave function. The actual detection is a particle function. When the electron is actually detected is a wave function collapse. That’s just a term we call it because no one really knows what the frakk is going on. Excuse my Battlestar Galactica.