Here's the answer

April 28, 2020   photos  

First of all, the number 4 is the correct one because the live will pass through a circuit breaker, then switch to reach the lamp and it will create a closed contact with the neutral connected to the other part of the lamp. 1-4 but the color of the neutral conductor is blue, while the phase one can be black, brown and grey the same applies to the returns of position switches. That's why the fourth one is the correct one.