A proficient engineer can easily design skeletal structures that are more functional than those currently found in the forelimbs of such diverse mammals as horses, whales, and bats. The actual forelimbs of these mammals do not seem to be optimally arranged because .A) natural selection has not had sufficient time to create the optimal design in each case, but will do so given enough time
B) in many cases, phenotype is determined by genotype and the environment
C) though we may not consider the fit between the current skeletal arrangements and their functions excellent, we should not doubt that natural selection ultimately produces the best design
D) natural selection is generally limited to modifying structures that were present in previous generations and in previous species

D) natural selection is generally limited to modifying structures that were present in previous generations and in previous species

Explanation:

A proficient engineer can easily design skeletal structures that are more functional than those currently found in the forelimbs of such diverse mammals as horses, whales, and bats. The actual forelimbs of these mammals do not seem to be optimally arranged because natural selection is generally limited to modifying structures that were present in previous generations and in previous species.

D. Natural selection is generally limited to modifying structures that were present in previous generations and in previous species

Explanation:

Natural selection can be explained or described as a situation whereby the organisms that are more adapted to their environment are known to be more likely survive and transfer the heritable traits to their young ones through reproduction.

Therefore at the long run, the organisms with the most adapted features or traits will dominate that particular environment.

This means that, the adapted traits may be modified in the new organisms produced.

So, in this case, the engineer can easily design skeletal design that are more functional than those currently found in the forelimbs, since he is the one designing , he is capable of making his own decision on what and how he wants the skeletal design to look like, because it does not involve natural selection.

did you fail the test? xd

well the answer is 2!