To indicate a conclusion, which of the following transitions is appropriate?

The choice of "To summarize" is appropriate for indicating a conclusion because it explicitly signals to the reader that the information presented is being wrapped up and key points are being distilled. Transitions that suggest summarizing serve to reinforce the main ideas by providing a concise overview of the discussion or argument that has been laid out. This helps to clarify the main takeaways and solidify the argument's impact on the reader.

The other options, while they serve important purposes in writing, do not convey the same conclusive implication. For instance, "In addition" is used to introduce additional information rather than to summarize or conclude. "Whereas" contrasts two ideas, which is not typically associated with drawing a conclusion. Lastly, "In comparison" indicates a discussion about similarities or differences, but does not provide closure or a summary of the information discussed.