XYZ, aquatic mammals inhabiting Florida’s rivers and coastal waters, swim close to the surface and are frequently killed in collisions with boats. To address the problem, boat traffic in XYZ-populated waters is being required to maintain very low speeds. Unfortunately, XYZs are unable to hear low-pitched sounds and a boat’s sound lowers in pitch as the boats slows. Therefore, this approach may in fact make things worse rather than better.

Question) Which of the following if true would strengthen the conclusion?

a) The areas where boats would have to maintain low speeds were decided partly on the basis of XYZ-population estimates and partly from numbers of reported collisions between XYZ and boats.

b) Because the water hyacinth that XYZ feed on grow best in water that is nearly still, water hyacinth beds can be disturbed or damaged by fast-moving boat traffic.

c) Over the last several decades, boat traffic in Florida’s coastal waters has been increasing almost continuously and now represents the greater threat to the endangered XYZ population.

d) The sound of a boat engine generally travels much further under water than it does through the air.

e) When experimenters exposed XYZs to the recorded sounds of boats moving at various speeds, the creature were unable to discern the sounds over normal background noise.

Yeah E makes most sense but I was hoping if someone could provide an explanation

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As you pointed out that this approach [slow boats] would make situation worse rather than improve it so if the mammal are not able to distinguish than slow boats are as bad as fast boats so it doesn't really effect [as you mentioned the answer should be] but since it doesn't effect then it would mean that it just wouldn't improve the situation. Is that what we are looking for in the answer - since no change in situation so he it doesn't improve it hence it does the opposite i.e. makes it worse?

^^^ you are right . the conclusion for the arguments is "this approach may in fact make things worse rather than better"
E doesn't necessarily make things worse but thats the only one in the answer choices that is very close to the expected option.
none of the other answer choices even fit the argument
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good explanation !!!

Exactly nikhilsamuel89 .If the XYZ is unable to distinguish between low and high speed .It does not matter at what speed the boats are travelling .Someone pls give a valid explanation .
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+1 if you like my explanation .Thanks

I chose option E but didn't liked the grammar in it.

"When experimenters exposed XYZs to the recorded sounds of boats moving at various speeds, the creature were unable to discern the sounds over normal background noise. "

creature is singular; why does the sentence uses plurel were?
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premise : xyz swims close to water surface and are frequently killed by collision with speed boat
premise :XYZs are unable to hear low-pitched sounds and a boat’s sound lowers in pitch as the boats slows

conclusion : the approach of maintaining low speed is making problem of collision is actually worse

thus a strengthener would either
1. provide an evidence or support that event that additional support to prove conclusion ( slow speed doesn't prevent collision)
or 2. it would close/negate any alternate reason for collision. (may be suicidal tendency of xyz is infact the cause )

let's search out for any of these in answers

a) The areas where boats would have to maintain low speeds were decided partly on the basis of XYZ-population estimates and partly from numbers of reported collisions between XYZ and boats. [color=#800080] even if areas were determined using this logic, it does not provide any support to the theory tht low speeds doesn't help in solving of collision. Out of scope

b) Because the water hyacinth that XYZ feed on grow best in water that is nearly still, water hyacinth beds can be disturbed or damaged by fast-moving boat traffic. this option is again out of scope, thou it may be helpful in increasing the population of xyz , but our stimulus is manily concerned with accident btw xyz and slow moving boats.

c) Over the last several decades, boat traffic in Florida’s coastal waters has been increasing almost continuously and now represents the greater threat to the endangered XYZ population. again same as B. it does not address the issue of collision btw slow moving boats n xyz

d) The sound of a boat engine generally travels much further under water than it does through the air. out of scope we are concerned with pitch of sound rather than its speed

e) When experimenters exposed XYZs to the recorded sounds of boats moving at various speeds, the creature were unable to discern the sounds over normal background noise if xyz cannot distinguish btw various boat sounds over background noise, then it doesn't make any difference if boat travels slower or faster. hence it doesn't destroy conclusion Although slow speed doesn't make matter worse but it doesn't improve it either.

Hence out of all the choices only one which comes close by is E [/color]

e) When experimenters exposed XYZs to the recorded sounds of boats moving at various speeds, the creature were unable to discern the sounds over normal background noise.

Option E ties a new evidence to the conclusion that the XYZs can't differentiate the sounds over the normal noise (Something which may be present in the waters).

the same question
stem assumes that XYZ does hear the noise from fast-speed boat
E says that it's not true
so E can't be correct
please clarify