Final answer:
Cooked food must be cooled to 70°F (21°C) within 2 hours. This rapid cooling is necessary to prevent bacterial growth that occurs between 40°F and 140°F. A thermometer should be used to ensure food reaches safe temperatures.
Step-by-step explanation:
Regarding the cooling of cooked time/temperature control for safety food, it is important to follow strict guidelines to prevent the rapid multiplication of microorganisms. Foods contaminated with bacteria may become hazardous if kept at temperatures that promote bacterial growth. Consequently, the correct answer to the student's question is c. 70°F (21°C). This temperature must be reached within 2 hours before further cooling to 41°F (5°C) within a total of six hours.
A key aspect to consider is that bacteria generally multiply most rapidly at temperatures between about 40°F and 140°F (4°C and 60°C). As such, it is essential to cool foods quickly through the 'danger zone' to prevent foodborne illness. Utilizing a thermometer is strongly recommended to ensure that food reaches safe internal temperatures for both cooling and cooking.