The chanterelle, a type of wild mushroom, grows beneath host trees suc

Premise1: C grows beneath D.
Premise2: D provides sugar to C.
Premise3: C provides water to D.
Premise4: Relationship is mutual.
Conclusion: C beneath D seriously endangers the D.

(A) The number of wild mushrooms harvested has increased in recent years.
Does not point what happens to D because of this phenomenon, so not relavant.

(B) Chanterelles grow not only beneath Douglas firs but also beneath other host trees.
Does not point why C beneath D is bad for D.

(C) Many types of wild mushrooms are found only in forests and cannot easily be grown elsewhere.
Environment in which C grows does not explains why for D it is bad.

(D) The harvesting of wild mushrooms stimulates future growth of those mushrooms.
This may be true, however it does not attack conclusion at all on how this C and D relationship is bad for D.

(E) Young Douglas fir seedlings die without the nutrients and water provided by chanterelle filaments.
This destroys the conclusion. Conclusion says because of C and D relationship, D dies, however, this tells us because of relationship D infact survives because of relationship.

IMO E.

If the harvesting of wild mushrooms stimulates future growth of those mushrooms then there is not reason to worry about the endangerement of the Douglas Fir! So "D" counters the conclusion drawn above.

D. the passage says "harvesting mushroom endangers the tree's life". D says harvesting mushroom stimulates more mushrooms. So harvesting is not a problem.

I agree that E supports the argument,,As conclusion is cutting the trees would endanger the tree,,,,We have find option which doesn't endanger the tree how come the option D is applicable??? The harvesting of wild mushrooms stimulates future growth of those mushrooms. Kindly brief it, thank you

The argument says that harvesting the mushrooms will endanger the tree because after being harvested, there wont be any mushrooms to provide the tree with nutrients.

Choice D says that harvesting the mushrooms would lead to further growth of mushrooms. Hence the argument's conclusion is rendered incorrect.

What is the conclusion?
"harvesting the mushroom seriously endangers these trees"

To weaken it we need to provide an explanation why harvesting the mushroom may not endanger these trees.
We know that mushrooms and trees benefit each other.
Option (D) tells us that harvesting of wild mushrooms stimulates future growth of those mushrooms. This means that even if you harvest the mushrooms, they will grow back and hence the beneficial relation will continue or perhaps even become better since harvesting stimulates future growth.
This weakens the statement that harvesting the mushrooms endangers these trees.

None of the other options weaken our conclusion.

(E) strengthens the conclusion, not weakens it.
The conclusion is "harvesting the mushroom seriously endangers these trees". You could easily follow it up with option (E): "Young Douglas fir seedlings die without the nutrients and water provided by chanterelle filaments". It provides support to my conclusion that yes, harvesting the mushroom might endanger the Douglas fir trees because there seedlings will die. We need to weaken the conclusion so (E) doesn't work at all.

Conclusion - Harvesting the chanterelles growing beneath a Douglas fir seriously endangers the tree.

We need to find a weakener i.e. something which should say that harvesting the chanterelles would in turn do greater good to the host tree by more than compensating for the loss of nutrients and water OR something which should say that even though chanterelles are providing water and nutrients but in turn are committing greater harm to the host tree. Any answer along any of these 2 lines of reasoning would be apt.
Option 'D' is the correct answer as it says that harvesting is necessary as it stimulates the growth of more such mushrooms and this is along the lines of reasoning of the 1st statement made above.

The argument assumes that the tree is dependent on the mushrooms.

The logic of D is this - if you stop harvesting the mushrooms the mushrooms will not grow thus endangering the tree, so you need to keep harvesting the mushrooms to sustain the tree.

E is a strengthener- E validates the assumption that the trees are dependent on the mushrooms for survival, solidifying the argument. E is then obviously incorrect.

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