Final answer:
Humans adapting to high-latitude environments experienced natural selection for genes linked to lighter skin pigmentation for Vitamin D synthesis and improved fatty acid metabolism for energy regulation in cold climates. The answer is option C.
Step-by-step explanation:
The movement of humans into high-latitude environments resulted in natural selection for genes related to reduced skin pigmentation and improved fatty acid metabolism. As humans migrated away from the equator, they were exposed to less ultraviolet radiation, leading to lighter skin pigmentation, which aids in synthesizing enough Vitamin D in environments with less sunlight.
Additionally, certain genetic adaptations, like the PPARA mutation found in the Tibetan population, correlate with improved fatty acid metabolism, an adaptation that may assist with energy regulation in cold environments.