I can't give you the correct answer but you can guess for it, cause I can give you the the scop of the length of KL.
So, as we know this;
The sum of the two sides of a triangle is greater than the third and the difference between the two sides is less than the third.
10+5 >= KL >= 10-5
15 >= KL >= 5
based on your option, the answer should be:
9 in
