Mature white pines intercept almost all the sunlight that shines on them. They leave a deep litter that dries readily...

Ravi on January 21, 2020

@Lucas,

Let's look at (A).

(A) says, "the ages of the trees in the stand do not differ from each
other by much more than the length of time it takes a white pine to
grow to maturity"

Based on the information in the stimulus, (A) all is all but
guaranteed to be true. Until the first pines reached maturity, other
pines were still able to grow; however, once the first pines did reach
maturity, the other pines could no longer grow. Thus, (A) most
logically concludes the argument and is the correct answer choice.

Hope this helps. Let us know if you have any other questions!