Which tool is described as thermal imagers (differences in temp)?

• A. Seismic devices
• B. Listening devices
• C. Cameras (fiber optics)
• D. Thermal imagers

Answer: (D)

Thermal imagers detect infrared energy emitted by objects and convert temperature differences into an image, so you can see heat patterns and hot spots that aren’t visible to the naked eye. The description “thermal imagers (differences in temp)” directly matches this capability, making it the best fit. Seismic devices read ground vibrations, listening devices capture sound, and fiber optic cameras image in the visible spectrum rather than heat, so they don’t describe measuring temperature differences.