Final answer:
Beavers, having abundant access to water, would be expected to have shorter loops of Henle in their nephrons compared to humans. This adaptation reflects a reduced need for water conservation.
Step-by-step explanation:
The ability of beavers to conserve water is not as crucial as it is for humans, because beavers have a more constant access to water. Therefore, the structure of their kidneys reflects this difference in necessity. When comparing the nephrons of beavers to humans, we would expect beavers to have shorter loops of Henle in their nephrons.
Juxtamedullary nephrons are known to have longer loops of Henle, which helps in concentrating urine by allowing more time for water and solutes to be reabsorbed. Beavers, who do not need to conserve water to the same extent, would therefore have less of a need for these longer loops and consequently have shorter nephron loops overall.
The correct answer to the question is that beavers would be expected to have C. shorter nephrons loops than humans, as these are less necessary for animals that do not need to conserve as much water.