Correct Answer  Option 3 : 40 dB/dec
Given:
Concept:
 The lowfrequency approximation is called the lowfrequency asymptote.

It is measured at frequencies close to zero (low frequency). ∴ The lowfrequency asymptote slope depends upon the poles or zeros at the origin.
 ADD FROM LMS
Analysis:
\(G\left( s \right) = \frac{{6\left( {{s^2} + 10s + 100} \right)}}{{{s^2}\left( {50{s^2} + 15s + 1} \right)}}\)
As the G(s) function has two poles at the origin:
So, the low freq. asymptote slope will be:
= 2(20)
= 40 dB/decode