As per answer provided L is safe.
The bullet fired by the sniper can hit the person standing at point L - i.e. at 90 ft from origin.
It is impossible (ambiguous) to assume bullet can or cannot hurt one persona and then hit the feet of other person in line assuming it as a straight line unless it is clearly specified.
I think the question should clearly specify. - else the score get affected due to ambiguity in question itself.
Regards
Anuj