Viruses can have beneficial effects. For example, some kill more complex microorganisms, some of which are deadly to humans. But viruses have such simple structures that replacing just a few of a beneficial virus’s several million atoms can make it deadly to humans. Clearly, since alterations of greater complexity than this are commonly produce by random mutations, any virus could easily become dangerous to humans.
The para is NOT extreme, that is, it nowhere speaks of terms such as ALL or NONE, and this question is about COULD be true, so in all probability our answer should be something extreme, because otherwise almost everything could be trueIf the statements above are true, then each of the following statements could also be true EXCEPT:
(A) Random mutation makes
some deadly viruses beneficial to humans.
(B)
Some organisms of greater complexity than viruses are no more likely than viruses to undergo significant alterations through random mutation.
(C)
Some microorganisms that are more complex than viruses are beneficial to humans.
(D)
Some viruses that fail to kill other viruses that are deadly to humans are nevertheless beneficial to humans.
(E)
No virus that is deadly to organisms of greater complexity than itself is beneficial to humans.
If you look at the choices, A to D are using term SOME, so they are NOT extreme.... A to D, therefore, can be true.
E talks of NO virus, so too extreme to fall into ' could be true'..
E
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