The heat capacity of a sample should be divided by which quantity to find the specific heat capacity?

The specific heat capacity is defined as the amount of heat needed to raise the temperature of one gram of a given substance one degree Celsius (or Kelvin). It is expressed in units of energy per °C and gram. While the heat capacity of a sample is the heat needed to increase the temperature of the whole sample it is expressed in units of energy per °C. So, the heat capacity shall be divided by the mass of the substance in grams to find the specific heat capacity, This is specific heat / mass in grams --> heat capacity.

B. a graduated substance