For a negative feedback system shown in Figure,the equivalent transfer function is:

• A. \(\frac {s^3 + 5s^2 + 6s}{s^3 + 7s^2 + 12s + 3}\)
• B. \(\frac {s^3 + 5s^2 + 6s}{s^3 + 5s^2 + 4s - 3}\)
• C. \(\frac {s^2 + 5s + 4}{s^3 + 7s^2 + 12s + 3}\)
• D. \(\frac {s^2 + 5s + 4}{s^3 + 5s^2 + 4s - 3}\)