Final answer:
A scientist studying the body's utilization of nutrients during a marathon is likely a Nutritionist, who focuses on diet's impact on performance.
Step-by-step explanation:
The scientist who wants to study how the body uses foods and fluids during a marathon run is most likely a Nutritionist. This type of scientist specializes in understanding how nutrients and diet affect the body's performance and well-being. In the context of athletics, a nutritionist can provide valuable insights into the best practices for fueling the body before, during, and after long periods of physical exertion, such as a marathon.
Mrs. Sullivan's job title at TAMU is Professor. She is most likely a professor in the field of Nutrition since she studies how the body uses foods and fluids.