A newborn kangaroo, or joey, is born after a short gestation period of only 39 days. At this stage, the joey’s hind limbs are not well developed, but its forelimbs are well developed, so that it can can climb from the cloaca into its mother’s pouch for further development. The recent discovery that ancient marsupial lions were also born with only their forelimbs developed supports the hypothesis that newborn marsupial lions must also have needed to climb into their mothers’ pouches.

The argument in this passage relies on which of the following assumptions?

[A] All animals that are born after a short gestation period are born with some parts of their bodies underdeveloped.
[B] Well developed forelimbs would have been more advantageous to ancient marsupial lions than well developed hind limbs would have been.
[C] If the newborn marsupial lion did not climb into its mother’s pouch, then paleontologists would be able to find evidence of this fact.
[D] Newborn marsupial lions that crawled into their mothers’ pouches could not have done so had they not had only their forelimbs developed at birth.
[E] Newborn marsupial lions would not have had only their forelimbs developed if this development were of no use to the marsupial lions.
_________________

petrifiedbutstanding

we need to find an assumption that supports the fact that
newborn marsupial lions need strong forelimbs to climb into their mothers’ pouches.

[A] All animals that are born after a short gestation period are born with some parts of their bodies underdeveloped. all animals and some part underdeveloped => deviates from the qsns at hand , is out of scope
[B] Well developed forelimbs would have been more advantageous to ancient marsupial lions than well developed hind limbs would have been. we cant comment on how hind limbs would have helped and this is not the assumption we can base our answer on
[C] If the newborn marsupial lion did not climb into its mother’s pouch, then paleontologists would be able to find evidence of this fact. this is not an assumption, if we dont have evidence for it does not mean it cannot happen BUT this tell us to assume that ok the marsupial did climb into the pouch but does not answer that wether it used its forelimbs or not
[D] Newborn marsupial lions that crawled into their mothers’ pouches could not have done so had they not had only their forelimbs developed at birth.ok, they might not be able to do so, but we dont have concrete evidence saying that lions did climb into the pouch
[E] Newborn marsupial lions would not have had only their forelimbs developed if this development were of no use to the marsupial lions.this is the closest to the answer, it tells us that the developed forelimbs solved a purpose and the only purpose we can think of is that it helped the lions climb into the pouch

so answer = E

oh ok.. that helps. thanks a ton.
_________________

petrifiedbutstanding