Given Afreen's background as a chemist and her passion for solving climate change, the best career option among the responses provided would be:
C. Oceanography would be the best because it focuses on ocean circulation and abiotic components.
Oceanography often involves the study of chemical processes in the ocean, including how climate change affects these processes. This aligns well with her background in chemistry and her interest in addressing climate change. While marine biology and ecology also contribute to understanding climate change impacts, oceanography's focus on abiotic factors and ocean circulation directly relates to environmental chemistry and climate systems.