Final answer:
The term "12D" is used in microbiology to indicate the amount of time needed to achieve a 12-log reduction, which translates to killing 90% of the population 12 times over. The correct answer is D. kill 90% of the population.
Step-by-step explanation:
The question relates to the concept of decimal reduction time (DRT) or D-value in microbiology, specifically regarding microbial death curves and control protocols. The 12D value mentioned in the question refers to the amount of time required to reduce a specific population by 12 orders of magnitude, which equates to killing 90% of the population 12 times over. Therefore, the correct answer to the question "12D is the amount of time required to:" is D. kill 90% of the population, repeated for twelve iterations or reductions of one order of magnitude each.
The decimal reduction time is defined as the amount of time it takes for a specific protocol to produce a one order-of-magnitude decrease in the number of organisms, effectively killing 90% of the targeted microbial population. Understanding the DRT is critical for assessing the efficacy of sterilization and disinfection processes in various settings, including healthcare and food safety.