Explanation:

- Geeta Ramji was a renowned scientist in the field of medical research, with a focus on HIV prevention and treatment. Her work was significant in developing methods to combat the virus, which has been crucial in saving lives.

- Option 1: Developmental Economy: This field involves understanding and improving the economic situations of developing countries. It is not directly related to Ramji’s work.

- Option 2: Nuclear Physics: This area focuses on the properties and behaviors of atomic nuclei. Geeta Ramji was not known for her contributions here.

- Option 3: Virus Science: Geeta Ramji was highly esteemed for her advancements in HIV virus research. Her contributions to understanding and combating the virus were internationally recognized.

- Option 4: Space Research: This involves the study of outer space, space exploration, and related technologies. This was not Geeta Ramji's field of expertise.