The effective means in education communication is

Black board writing
Audio-visual means
Audio means
Visual means

The correct answer is: B. Audio-visual means

Audio-visual means are the most effective means of education communication because they combine the power of sound and images to create a more engaging and memorable learning experience. Audio-visual materials can be used to present information in a variety of ways, including lectures, presentations, videos, and podcasts. They can also be used to create interactive learning experiences that allow students to explore and learn at their own pace.

Blackboard writing is a less effective means of education communication because it is a one-way form of communication that does not allow for interaction between the teacher and the students. Blackboard writing can be useful for providing students with basic information, but it is not an effective way to engage students or to help them learn complex concepts.

Audio means are also less effective than audio-visual means because they do not provide students with visual cues. Audio materials can be useful for providing students with background information or for helping them to learn new vocabulary, but they are not an effective way to help students understand complex concepts.

Visual means are more effective than audio means, but they are not as effective as audio-visual means. Visual materials can be useful for providing students with a visual representation of information, but they do not provide students with the same level of engagement as audio-visual materials.

In conclusion, audio-visual means are the most effective means of education communication because they combine the power of sound and images to create a more engaging and memorable learning experience.