pareekbharat86 wrote:The chanterelle, a type of wild mushroom, grows beneath host trees such as the Douglas fir, which provide it with necessary sugars. The underground filaments of chanterelles, which extract the sugars, in turn provide nutrients and water for their hosts. Because of this mutually beneficial relationship, harvesting the chanterelles growing beneath a Douglas fir seriously endangers the tree.

Our attempt here is to weaken the red part highlighted above.

(A) The number of wild mushrooms harvested has increased in recent years.

Irrelevant under the current context.

(B) Chanterelles grow not only beneath Douglas firs but also beneath other host trees.

Irrelevant under the current context.

(C) Many types of wild mushrooms are found only in forests and cannot easily be grown elsewhere.

Irrelevant , doesn't even touch a part of the conclusion stated above.

(D) The harvesting of wild mushrooms stimulates future growth of those mushrooms.

We know that wild mushroom depends on Douglas fir , thus for the growth of Wild Mushrooms survival of Douglas fir is essential and vice Versa.

We also know from the passage that , " which provide it with necessary sugars. The underground filaments of chanterelles, which extract the sugars, in turn provide nutrients and water for their hosts. "

Thus survival and growth of the Douglas fir is vital as well as essential for future growth the wild mushrooms.

(E) Young Douglas fir seedlings die without the nutrients and water provided by chanterelle filaments.

Might be possible , we aren't sure about it ...

Though the statement provides vital information it doesn't weaken / challenge the red highlighted part. Infact this statement simply support the conclusion arrived at in the passage above.


So D seems to be the best choice..