Final answer:
It is impossible to tell from the provided choices alone which confirms the replacement of one air mass by another. Indicators such as temperature drop, humidity change, or wind pattern shifts are typically observed, but they are not among the given options.
Step-by-step explanation:
The question asks which choice confirms that one air mass is being replaced by another air mass in a given area. The presence of an air mass affects several atmospheric conditions, such as temperature, moisture, and pressure. However, a sudden change in these conditions typically signals the replacement of one air mass by another.
Choice A, an increase in wind, might indicate that an air mass is moving, but it does not necessarily confirm a replacement by another air mass. Choice B, high air pressure, and Choice C, high air temperature, are characteristics that can be associated with different types of air masses but do not indicate the replacement process on their own. Therefore, based on the information typically observable during such an event, the correct answer would be It is impossible to tell from these given choices alone without additional context or data.
There are several key indicators not listed in the options that meteorologists use to determine the movement and replacement of air masses, such as a sudden drop in temperature, change in humidity, or a change in wind patterns signaled by shifts in wind direction. Weather fronts, which are the transitional zones between two air masses, often bring these changes and can be identified on a weather map.