In the scenario pictured in the attachment, which I often encounter:
I (green) am passing an intersection while riding to the right/rear of a bus or other large vehicle, and an oncoming car/vehicle (red) is waiting to make left turn. If I don't want to wait, then I usually "take advantage" of the bus/truck and follow through next to it. But sometimes this can be dangerous, as the turning car's driver may not be aware of my presence, so if he is also impatient, may hit me.
So in such scenario, is it safer to wait behind the bus so that the turning car driver can see me? (3 possible positions of bike)
I either:
1) I usually choose a position between A and B, giving me room to hit the brakes and have the big vehicle pass in front of me if it starts merging into my space and keeping me in the shadow of the big vehicle as far as the oncoming turning traffic or:
2) take the lane behind the big vehicle, positioning myself to the left of the lane so that I can be seen by the oncoming traffic.
Which I choose varies depending on the exact traffic situation at that moment and my mood.