What type of slope has denser vegetation and typically lower fuel temperatures?

The correct choice is B, as north-facing slopes typically receive less direct sunlight throughout the day compared to other slopes. This results in cooler temperatures and higher moisture retention in vegetation, leading to denser plant growth and lower overall fuel temperatures. The cooler and more humid conditions on north-facing slopes contribute to the preservation of moisture in the vegetation, which can help reduce the flammability of the fuel.

In contrast, south-facing slopes tend to be warmer and drier, which typically results in less dense vegetation and higher fuel temperatures. East-facing and west-facing slopes also experience more direct sunlight, but they have varying exposure throughout the day that can influence temperature and moisture retention. However, north-facing slopes are the most recognized for having denser vegetation and cooler, moister conditions, making them distinct in wildland fire behavior studies.