What are the common units used to measure atmosphere?

The correct answer is grounded in the units commonly used to quantify atmospheric pressure, which is a critical component in fields like meteorology and aviation. Inches of Mercury (inHg), Millibars (mb), and Hectopascals (hPa) are all standard units for measuring atmospheric pressure.

Inches of Mercury is often used in aviation and certain weather reports in the United States. Millibars and Hectopascals are widely used worldwide, particularly in meteorological contexts, making them essential for understanding weather patterns and forecasting.

This selection emphasizes units that are directly involved in measuring pressure, a fundamental atmospheric property. Other options contain units not relevant to atmospheric pressure measurement. For instance, Volts relate to electrical potential, Grams pertain to mass, and volumetric units like Milliliters and Liters are used for measuring liquids rather than pressure. Thus, the accuracy of the units related to atmospheric measurements is critical, affirming the correctness of the chosen answer.