How do you get to the answer

Let's go through the answers one by one. A tells us that V is only effective against 2 species. We know this isn't true because it has been tested against EVERY species in North America, which are more than 4,000. B tells us that not all North American cockroach species can be controlled by Roach Ender. The letter author tells us that it is effective against all of them, so this can't be true. C could be true. We don't know for sure it was the V in the RE product that controlled all of them, but it could be. D is false because we know that RE, which has V, has been used against all the North American species. E is false because we know it's been tested against the MORE than 4,000 species in North America, not exactly 4,000.

Test comment

Hi, Don't understand how answer choice A is incorrect. Passage says, "vexone has been utilized effectively for almost a decade against all of the species that infest North America" Answer A says V is only effective against 2 species. Isn't this in conflict with the Letter's point of view?

Disregard, I misunderstood the question stem. I thought understanding the passage was difficult enough, lol