explanation please

This is a Paradox question so we are looking for a possible explanation to the discrepancy in the stimulus. What is the discrepancy? That rats fed high doses of saccharin develop silicate crystals and form tumors but mice fed high doses of saccharin do not. So let's take a look at (A), which states, "Urine proteins that react with saccharin to form silicate crystals are found in rats but not in mice." This would definitely serve as a possible explanation as to why we see cancer in rats fed high doses of saccharin but not in mice. Mice do not have the urine proteins that react with saccharin to form silicate crystals. So (A) would be the correct answer. Hope that helps! Please let us know if you have any other questions.

Could you please explain why E is not the correct answer?

(E) is completely irrelevant. This is not about "other artificial sweeteners." This is about saccharin. Hope that helps! Please let us know if you have any other questions.