To find the resistance of a galvanometer by the half-deflection method,the following circuit is used with resistances $R_1 = 9970\,\Omega$,$R_2 = 30\,\Omega$,and $R_3 = 0\,\Omega$. The deflection in the galvanometer is $d$. With $R_3 = 107\,\Omega$,the deflection changes to $\frac{d}{2}$. The galvanometer resistance is approximately ............... $\Omega$.

• A
  $107$
• B
  $137$
• C
  $53.5$
• D
  $77$