Question 5

@Samir, Rats fed high doses of saccharin develop crystals that are toxic to bladder cells. Mice fed high doses of saccharin do not exhibit the same negative consequences. (D) tells us "silicate crystals are toxic only to the cells lining the bladder and not to other bladder cells." This fact alone does not help the difference between rats and mice reactions as we have no information whether mice even develop silicate crystals, and we likewise have no information what type of cells - lining vs others are more likely to cause tumors. Does this help? Let me know if you have any further questions.