(d) The car would stop because unlike human drivers, a self-driving car would be programmed to avoid going so fast that it can't stop if a sudden obstacle would appear (aside from maybe something falling from the sky).
I trust sensors to detect icy conditions better than a trust myself.
[edit] Most bridges where I am have signs that explicitly warn that bridges freeze over. And people intuitively know... bridge + recent precipitation + cold whether = slow down. I don't know why a computer wouldn't know that.
If so - self-driving cars will be going much slower than manualy driven cars most of the time, which will probably hurt adoption.
I would like this to be the case, but I guess car companies will agree to some compromise to speed up adoption, and corner cases will be there. Should the software ignore them, or plan for them (= "planning to kill you").