Correct Answer : Option (B) : 2
Explanation : For the above equation, we need to find the roots by creating the Routh's array table. The given equation is: s^3 + Ks^2 + 5s + 10
The table is given below:

For the system to be critically stable, we will put (5K -10)/K = 0
5K - 10 = 0
5K = 10
K = 2
The value of K for which the system is said to be critically stable is 2.