Answer: Option (2) is correct.
Explanation:
Since we have given that
KLM is a right triangle, in which KM = 15, and ln is an altitude.
As we know that for right angled triangle, there are 3 conditions :

So, According to the options ,
Put LM = 12, NM = 9,

Since, it satisfies that KLM is a right triangle.
Hence, Option (2) is correct.