[单选题]
What inductance is necessary in series with a 500-W resistor foemrah9.m, pzr9):vj h7oi mc8)fte6 pr a phase angle o m8 azme9ct7)ivpjohrm9.)fr :p 6 h,et:t 8s i3:, ,2qleou xpe(sfboo psuf8et(:o,ib3l,q t x:s 2ef $40^{\circ}$ at 10 kHz?
A. $84 \; mH$
B. $46 \; mH$
C. $20 \; mH$
D. $6.7 \; mH$
