Final answer:
Hot food in a self-service area should be held at a minimum temperature of 135°F (57°C) to prevent bacterial growth.
Step-by-step explanation:
The minimum temperature at which hot food should be held in a self-service area is b. 135°F (57°C). This temperature is necessary to prevent the rapid multiplication of bacteria, which typically occurs between 40 and 140 degrees Fahrenheit (4 and 60 degrees Celsius). Perishable hot foods that remain below this temperature for more than two hours may become dangerous to eat due to bacterial growth.