Which of the following would NOT be a valid inference based on a reading passage?

The option that reflects a valid inference based on a reading passage involves using available evidence to support conclusions. Inference is fundamentally tied to observation and reasoning; it requires a logical connection to be made between the information presented in the text and the conclusion drawn. For instance, identifying themes, drawing conclusions, and connecting ideas to prior knowledge all hinge on the support provided within the text.

Assuming facts without supporting evidence, on the other hand, constitutes a fallacy in inference. It involves making claims that are not substantiated by the passage, thus leading to a conclusion that lacks a factual basis. Inferences should always be rooted in the context and details provided by the text to ensure accuracy and relevance in understanding the author's intent. Therefore, option B is not a valid inference because it disregards the essential requirement of having evidence to back up the assumptions made.