One of the two identical conducting wires of length $L$ is bent in the form of a circular loop and the other one into a circular coil of $N$ identical turns. If the same current $i$ is passed in both,the ratio of the magnetic field at the center of the loop $(B_L)$ to that at the center of the coil $(B_C)$,i.e.,$\frac{B_L}{B_C}$ will be:

• A
  $N$
• B
  $\frac{1}{N}$
• C
  $N^2$
• D
  $\frac{1}{N^2}$