(b) – for me
Looking around helps, as does little 'wobbles' from time to time to show that you need a bit of space. If I'm in any doubt about cars having enough space to pass safely without squeezing me, then I'll check behind and drift out a little.
Agree. Little wobbles are good to show that you actually take up a metre or so of road space, about half a lane.
In the last year or so, when I'm driving, I've also found myself drifting more towards the centreline when there are cyclists coming towards me with a car trying to squeeze past behind them.
Disagree. If the overtaking driver has commited to the overtake then you are at risk of hitting them head-on or forcing them back into the area of the cyclist. You are also in the wrong if you are crossing the white line into on-comming traffic.