Concept:Radioisotopes are used as tracers or radiation sources in medicine, industry, and farming, but not in weather forecasting.
Explanation:In medicine, radioisotopes help in diagnosing and treating diseases.
In the oil industry, they trace the flow inside pipelines and detect leaks.
In agriculture, they are used for pest control and creating useful crop mutations.
Weather forecast depends on meteorological data, satellite images, and computer models.
Radioisotopes are not part of regular weather forecasting methods.
Answer:D. Weather forecast