For a lead compensator having a transfer function\({G_c}\left( s \right) = \left( {\frac{{s + {z_c}}}{{s + {p_c}}}} \right) = \frac{{\left( {s + \frac{1}{\tau }} \right)}}{{\left( {s + \frac{1}{{\alpha \tau }}} \right)}}\)1. \(\alpha = \frac{{{z_c}}}{{{p_c}}} < 1\)2. \(\alpha = \frac{{{z_c}}}{{{p_c}}} > 1\)3. τ > 04. τ < 0Which of the above are correct?

• A. 1 and 4
• B. 1 and 3
• C. 2 and 4
• D. 2 and 3