answer: a, but
a ball descending from 10 stories that hits you is going to hurt, and it doesn't matter which way you are standing or looking. With the distance the ball travels I am surprised more golfers don't use coloured balls designed to be more visible.
I have seen the same solution at the fabled Sand Pines (since renamed Florence Golf Links), where the area around 16G/17T is OB while playing the 18th.