Final answer:
Water vapor is particularly useful for tracking the flow of moisture across wide regions and helping identify the location of frontal boundaries.
Step-by-step explanation:
The correct answer is c. water vapor.
Water vapor is particularly useful for tracking the flow of moisture across wide regions and helping identify the location of frontal boundaries. Water vapor is an important component of the Earth's atmosphere and its distribution can provide valuable information about weather patterns and atmospheric conditions.
For example, infrared satellite imagery can detect water vapor in the atmosphere by measuring the amount of infrared radiation emitted by the water molecules. By tracking the movement of water vapor, meteorologists can better understand the dynamics of weather systems and make accurate forecasts.