This question

So the principle in answer choice (E) is "If Charles is certain of being able to solve Patrick's behavioral problem, then Charles does no understand why Patrick is behaving in this way." We would diagram it: CSP - > not UP. To see if that principle can be validly drawn from the passage we must look at our own diagrams of the passage and see if we can connect "being certain of solving someone else's problem" to not understanding why Patrick behaves in the way he does. The variable "CSP" is the sufficient condition in the contrapositive of the second principle rule. Therefore, we start there so we can connect "CSP" to "not UP." We see that the contrapositive is CSP - > not E. We can connect that to the contrapositive of the first principle rule through the transitive property to be: CSP - > not E - > not UP. Meaning: CSP - > not UP. Therefore, we can validly conclude the principle in answer choice (E) from the passage. I hope that helps! Let me know if you have any more questions!

Thanks Naz