@liwenwong28, this is a must be false question. The wrong answers are all things that could be true, and the right answer is something that cannot be true.
A is incorrect because the stimulus states that random mutation can make some beneficial viruses turn deadly. There isn't any information regarding whether or not the reverse is possible, so it could be true.
B is out because we know from the stimulus that viruses kill some more complex organisms, but we don't have any info about how and whether or not those more complex organisms mutate. This answer choice compares two things that were in the stimulus, but we have no info about this type of comparison, so it could be true.
C is out because we know from the stimulus that some viruses are beneficial to humans because they sometimes kill harmful organisms, but the problem is that there isn't any information about whether those microorganisms can be beneficial. Thus, this could be true.
D is out because we know that one way in which viruses can be beneficial is by killing things that kill humans. However, there's no information about whether other types of viruses might help humans. It could be true that other types of viruses do aid humans. Additionally, this answer choice discusses Killion viruses whereas the stimulus discusses viruses killing microorganisms. This is a different matter that's not discussed in the stimulus, so it could be true.
E is correct because the stimulus tells us that at least some viruses are beneficial to humans, and they're beneficial because they kill more complex microorganisms. E directly violates this concept, so this must be false (cannot be true).
