What is the primary purpose of using charts and diagrams instead of other tools to brainstorm for a research paper topic?

to ensure that the ideas follow a logical order.
to organize ideas based on relevance.
to visualize relationships among ideas.
to allow ideas to flow freely.
to explore a topic from different angles.

C .to visualize relationships among ideas

Explanation:

The use of a visual aid will help you understand better how related are the objects of the research. You don't really need a diagram to make something follow a logical order, nor to organize things based on relevance. It is also not needed to put the subject under a new light. The diagram and charts actually help you with comparisons more than anything.

what are the sentences?

the type of supporting detail is fact!