Identify the definition of sensitivity of a galvanometer from the following.

• A. Ratio of unit change in unknown resistance to the deflection in the galvanometer
• B. Ratio of unit change in unknown resistance to twice the deflection in the galvanometer
• C. Ratio of deflection in the galvanometer to the unit change in unknown resistance
• D. Ratio of deflection in the galvanometer to half the unit change in unknown resistance