The best claim is that the reddish-brown substance is not the same as either the fertilizer or the substance that makes up the pipes.
This prompt requires you to use all the evidence collected in a case about the appearance of a reddish-brown substance in water to identify what this substance is and the cause of it.
Based on this, the best claim is that this substance is not the same as either the fertilizer or the substance that makes up the pipes. Here are the reasons:
Note: This question is incomplete because some information is missing. However I can answer it based on my general prior knowledge.
Learn more about substances in: https://brainly.com/question/24372098