The decimal reduction time refers to the amount of time it takes to which of the following?

reduce a microbial population by 10%

reduce a microbial population by 0.1%

reduce a microbial population by 90%

completely eliminate a microbial population

The correct option is: reduce a microbial population by 90%

Explanation:

In a sterilization procedure, the decimal reduction time is the required time to achieve a log reduction i. e. reduce the microbial population by killing the 90% of the relevant microbial population, at the given set of conditions. Therefore, after the exposure time of 1 D, only 10% of the microbial population remains.