With an alternating voltage source of frequency $f$,an inductor $L$,a capacitor $C$,and a resistor $R$ are connected in series. The voltage leads the current by $45^{\circ}$. The value of $L$ is $(\tan 45^{\circ} = 1)$.

• A
  $\left(\frac{1+2 \pi fCR}{4 \pi^2 f^2 C}\right)$
• B
  $\left(\frac{1-2 \pi fCR}{4 \pi^2 f^2 C}\right)$
• C
  $\left(\frac{4 \pi^2 f^2 C}{1+2 \pi fCR}\right)$
• D
  $\left(\frac{4 \pi^2 f^2 C}{1-2 \pi fCR}\right)$