Final answer:
A physical anthropologist primarily studies the evolution of humans and other primates. This includes examining how human biology evolved alongside environmental usage and how different hominin species emerged and adapted over time.
Step-by-step explanation:
A physical anthropologist would be most likely to study C. The evolution of humans or other primates. Physical anthropologists are concerned with the adaption, variability, and evolution of humans and their living and fossil relatives. This includes researching how human biology evolved with environmental influences and understanding the biocultural aspects that are central to human life, such as the emergence and migration of different hominin species and the conditions that favored certain biological and cultural traits.
In the broader field of biological anthropology, various study areas contribute to our knowledge about human and nonhuman primates. For instance, primatology is essential to understanding our closest animal relatives—nonhuman primates—to gain insights into the shared biological and social traits with humans. Paleoanthropology, another area, focuses on the fossilized remains to chart the human evolutionary path.
Overall, the field is deeply rooted in evolutionary theory, following Charles Darwin's principles of natural selection, which underline how favorable traits are more likely to be passed down through generations. As a comprehensive discipline, biological anthropology examines the deep past to answer questions about our present and future as a species, emphasizing the interconnectedness of biology, behavior, culture, and evolution.