About The hierarchy: which sign wins when they conflict: which statement is correct?
A traffic light always outranks every traffic sign, even a sign that regulates something completely different from right of way (such as a closure or a speed limit).
If a junction has no sign and no working traffic light, no right-of-way rule applies — drivers must simply agree among themselves who goes first.
It is exactly the other way round: the traffic light wins over the priority sign.
On a green light you may always proceed, even if a traffic controller is signalling you to stop.
Explanation
trap: inverted hierarchy. It is exactly the other way round: the traffic light wins over the priority sign. If you enter on green, you do not have to give way to someone running the red light at that crossing (Book p.58)