Assume that the silicon diode in the circuit requires a minimum current of 1 mA to be above the knee point (0.7 V) of I-V characteristics. Also assume that the voltage across the diode is independent of current above the knee point. If ${\mathrm{V}}_{\mathrm{B}}$ = 5V, then the maximum value of R so that the voltage is above the knee point is

• A

  4.3 k$\mathrm{\Omega }$

• B

  2 k$\mathrm{\Omega }$

• C

  1 k$\mathrm{\Omega }$

• D

  0