Many antiviral medications are effective at killing only some strains

Hello my friend, I believe that either you copied the text of the argument incorrectly or you are testing our sentence correction skills.

Anyways the following argument would make much more sense, please edit your post and paste this:

Many antiviral medications are effective at killing only some strains of the targeted virus. If only some strains of a targeted virus are killed by a given medication, there is a danger that, through random mutation or the emergence of other strains from natural reservoirs, resistant strains will gradually dominate those vulnerable to medication. If the antiviral medications are continually administered, for example to humans or cattle, there is a significant risk that existing medications will grow ineffective, leaving doctors with no remedies for these diseases.


Let's get to the answer: The conclusion is , as always, the key to the correct answer.

A The same medicines are administered to both humans and cattle.
-we don't care about this at all.

B New medical developments will not effectively kill previously resistant strains.
- there we go this is the correct answer, if new medical developments would kill previously resistant strains then doctors have a remedy. The argument falls.

C Existing viruses will mutate to form resistant strains where none had existed before.
- we don't care what viruses do.

D Viruses cause more diseases than other forms of infection, such as bacteria, prions, and molds.
- totally irrelevant.

E Biotechnology and drug companies will work to develop new medications that attack resistant viral strains.
- The author doesn't assume that, he says that doctors won't have a remedy for resistant viral strains.

The answer is B.