What do you mean by electric discharge
please don't take any answer from the internet

When negative and positive charges meet, producing streaks of bright light and sound. This process is called an electric discharge. When the accumulation of charges between lower part of clouds and earth becomes large, it is sufficient to break the insulation of air.

the duration of a photographic flash is related to an rc time constant, which is 0.100 μs for a certain camera.

im guessing the west of station b