Vivian's teacher suggests that responsible students write assignments in a planner. This is an example of what type of communication?

The suggestion made by Vivian's teacher for responsible students to use a planner showcases the concept of positive reinforcement. Positive reinforcement involves providing support or encouragement in a way that promotes desirable behavior. In this case, the teacher is encouraging good organizational habits that align with the behavior of being responsible. By suggesting the use of a planner, the teacher is reinforcing the idea that students should manage their assignments effectively. This type of communication aims to motivate students to adopt positive habits that can lead to academic success.

The other options do not fit as well. Proactive feedback typically involves offering constructive critique based on a student's previous performance, while testimonials relate to sharing personal experiences or opinions to validate an idea or action. Name-calling refers to disparaging remarks that do not provide any constructive feedback or reinforcement. Each of these lacks the supportive and encouraging element that is foundational to the concept of positive reinforcement.