A speech outline should indicate the most important and the least important information according to which of the following principles?

The correct answer, which focuses on the principle of subordination, highlights the importance of structuring a speech outline in a way that clearly distinguishes between main ideas and supporting details. Subordination in an outline allows the speaker to prioritize information, ensuring that the audience understands which points are crucial to the overall message and which are supplementary.

In a well-structured outline, the most significant ideas are presented prominently while subordinate points provide necessary support, evidence, or elaboration. This hierarchy helps to maintain clarity and focus, guiding both the speaker and the audience through the speech's logical flow. By following the principle of subordination, the speaker can effectively communicate the relative importance of each part of the content, enhancing audience comprehension and retention.

This principle ultimately reinforces the organization of speech content, ensuring that ideas build upon one another in a coherent manner, which is essential for effective public speaking.