<Dd> "The patent is 52 pages long plus 35 pages of figures . The first 43 pages amount to a small treatise on feedback amplifiers!" </Dd> <P> There are many advantages to feedback in amplifiers . In design, the type of feedback and amount of feedback are carefully selected to weigh and optimize these various benefits . </P> <P> Though negative feedback has many advantages, amplifiers with feedback can oscillate . See the article on step response . They may even exhibit instability . Harry Nyquist of Bell Laboratories proposed the Nyquist stability criterion and the Nyquist plot that identify stable feedback systems, including amplifiers and control systems . </P> <P> The figure shows a simplified block diagram of a negative feedback amplifier . </P>

Which of the following best describes the idea of negative feedback in hormonal control