For small-signal operation around the dc bias point, the diode is modeled by a resistance equal to the

• A. Slope of the i-v characteristics of the diode at the bias point
• B. Square root of the slope of the i-v characteristics of the diode at the bias point
• C. Inverse of the slope of the i-v characteristics of the diode at the bias point
• D. Square root of the inverse of the slope of the i-v characteristics of the diode at the bias point