Question

Hi, I have to answer this question "why do we say that metabolism is the factor that most accounts for differences among species in the toxicity of some xenobiotics?


I don't understand what the question means- I understand all the words in the question, but I am confused what they are asking.

I think it means like why does the toxicity level of some xenobiotics differ in different species? not sure though, if I am wrong can someone re-phrase the question? thanks.