A system with unity feedback having open loop transfer function as G(s) = K(s+1)/s3+as2+2s+1. What values of 'K' and 'a' should be chosen so that the system oscillates ?

A system with unity feedback having open loop transfer function as G(s

1.	A system with unity feedback having open loop transfer function as G(s) = K(s+1)/s3+as2+2s+1. What values of 'K' and 'a' should be chosen so that the system oscillates ?
A.	K =2, a =1
B.	K =2, a =0.75
C.	K =4, a =1
D.	K =4, a =0.75
Answer» C. K =4, a =1