Correct Option: C

The freezer in a refrigerator is fitted near the top so that it can cool the whole interior by setting up convection currents. Most household freezers maintain temperatures from (-23 to -18 degree C), although some freezer-only units can achieve (-34 degree C), and lower. Refrigerators generally do not achieve lower than (-23 degree C), since the same coolant loop serves both compartments: Lowering the freezer compartment temperature excessively causes difficulties in maintaining above-freezing temperature in the refrigerator compartment. Domestic freezers can be included as a separate compartment in a refrigerator, or can be a separate appliance. Domestic freezers are generally upright units resembling refrigerators, or chests (resembling upright units laid on their backs). Many upright modern freezers come with an ice dispenser built into their door.