Safe Zone for wiring on vaulted walls.

[MikeSharp01]

Hit a small problem today that I am struggling to find the answer to; Our Garden Room has walls that extend all the way up to the vaulted ceiling and the ceiling has an axisymmetric pitch so I am wondering where the wiring safe zone is, is it A or B or C or some combination of all three / any two? Any definitive ideas anyone?

[ProDave]

I have always assumed B if there is no conventional ceiling.

[MikeSharp01]

Thanks Dave, I guess that is my preferred. I can find nothing from IET.

[bassanclan]

It has to be B