Final answer:
The air ahead of the cold front was relatively warm and had high dew points.
Step-by-step explanation:
Based on the information provided, the air ahead of the cold front was relatively warm. To determine the dew point, we need to consider the relative humidity. The importance of dew point is that air temperature cannot drop below a certain point without water vapor condensing out of the air. If the dew points were relatively high, it means that there was a significant amount of water vapor in the air, which would result in higher humidity. Therefore, the correct answer is b) High.