Nick Finnigan wrote:

You are driving (a motor vehicle) at a safe and legal speed, with no
other vehicles moving in your direction for 200 yards, approaching some
(green) traffic lights which have these two stop lines in front of them.
Then the lights change to amber; you move your foot to cover the brake
pedal, and realize that you can not (physically, and so safely) stop
before reaching the first stop line. You can, however, stop safely
before passing the second stop line. You can also get past the second
stop line before the lights change to red (based on experience).

What legal options do you have? Which is the best one?

Stop at the second line.

Though as the lines are so close together it's rarely as cut and dried
as this. Stopping halfway betwen would still allow a bike to fit in
front of you, and is worth doing if you can.

Colin McKenzie