**Core Concept**
The question is referring to a method of presenting information to an audience during a lecture, specifically using visual aids to facilitate learning and engagement.

**Why the Correct Answer is Right**
The correct answer is a type of educational chart that is flashed serially to the audience as the talk is being given. This method is often used to present complex information in a clear and concise manner, allowing the audience to focus on the key points being discussed. The serial flashing of the charts is designed to keep the audience engaged and to prevent information overload.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not refer to a specific type of educational chart that is flashed serially to an audience.
**Option B:** This option is incorrect because it is not a type of chart that is commonly used in educational settings.
**Option C:** This option is incorrect because it refers to a type of chart that is used for a different purpose.

**Clinical Pearl / High-Yield Fact**
The use of serially flashed educational charts can be an effective way to present complex information to an audience, but it requires careful planning and design to ensure that the information is clear and easy to understand.

**Correct Answer: B. Slides**