Which of the following would most likely be an entry in a topic outline?

None of the above.

To determine which of the following options would most likely be an entry in a topic outline, we need to understand what a topic outline is. A topic outline is a hierarchical structure that organizes main topics and subtopics in a logical and organized manner. It provides an overview of the content to be covered in a document, speech, or presentation.

Given that, let's analyze the options to identify which one would be the most suitable entry for a topic outline:

a) "Background information on renewable energy sources"
b) "The impact of climate change on global economies"
c) "Tips for reducing household energy consumption"

Analyzing the options, "Background information on renewable energy sources" seems to be the most suitable entry for a topic outline. It provides a specific topic that can be further expanded upon with relevant subtopics.

To select the correct option for a topic outline, it is important to analyze each option's relevance, specificity, and potential to be further elaborated upon. In this case, "Background information on renewable energy sources" meets these criteria and is thus the most likely entry in a topic outline.