## Core Concept
Plasma sterilization is a method used to eliminate microorganisms from medical instruments and equipment. The accuracy of this process is crucial to ensure patient safety. Assessing the effectiveness of plasma sterilization involves using biological indicators.

## Why the Correct Answer is Right
The correct answer, **B. Biological indicators**, is right because biological indicators, typically in the form of bacterial spores, are used to assess the efficacy of sterilization processes, including plasma sterilization. These indicators are highly resistant to the sterilization process and are used to verify that the process has achieved the required level of microbial kill.

## Why Each Wrong Option is Incorrect
* **Option A:** Chemical indicators are used to verify that items have been exposed to the sterilization process, but they do not confirm the effectiveness of the process in killing microorganisms.
* **Option C:** Physical indicators or monitors are used to ensure that the sterilization equipment is functioning correctly, but like chemical indicators, they do not directly assess microbial kill.
* **Option D:** While filters can be used in sterilization processes to remove microorganisms from liquids, they are not used to assess the accuracy of plasma sterilization.

## Clinical Pearl / High-Yield Fact
A key point to remember is that for sterilization processes, including plasma sterilization, **biological indicators** are the gold standard for verifying effectiveness. This is crucial for ensuring patient safety and preventing infections.

## Correct Answer: B. Biological indicators.