Final answer:
Serving utensils in continual use that are kept on a cleaned and sanitized food contact surface must be cleaned and sanitized every 4 hours.
Step-by-step explanation:
The correct answer is 2) 4 hours. Serving utensils in continual use that are kept on a cleaned and sanitized food contact surface must be cleaned and sanitized every 4 hours to ensure food safety. This is important to prevent the growth and spread of bacteria and other harmful microorganisms. Regular cleaning and sanitizing of utensils help maintain a hygienic and safe food preparation environment.