Letter to the Editor:  Your article on effective cockroach control states that vexone is effective against only one o...

I found the phrasing of this question difficult. It read, “Each of the following conflict with the letter writer’s view EXCEPT:,” which gave me pause because this section is all cannot be true, but it felt like a must be true question. I see in the correct answer explanation that it is a bizarro cannot be true. What is the difference between must be true and bizarro cannot be true? And should we approach them differently?