Which of the following is a MASINT data source?

• A. Social Media.
• B. Weather Forecasts.
• C. Nuclear Radiation.
• D. Economic Indicators.

Answer: (C)

MASINT relies on collecting measurements of physical phenomena with specialized sensors to produce data about objects or events. Nuclear radiation fits this, because there are sensors that detect and measure radiation levels and spectra, providing measurable signatures that can indicate radiological sources or nuclear activity. The other options come from human activities or model outputs rather than direct sensor measurements of physical phenomena: social media data are open-source communications, weather forecasts are predictive model results, and economic indicators reflect market data rather than sensor-based signatures. So nuclear radiation is the MASINT data source.