What factor increases the risk of mudslides after a wildfire?

The correct answer highlights that heavy rainfall significantly increases the risk of mudslides following a wildfire. After a fire, vegetation that normally helps to stabilize the soil is often removed, leaving the ground more susceptible to erosion. When heavy rain occurs, it can saturate the soil quickly, reducing its cohesion and making it easier for the loose, burned soil and debris to slide downhill. This combination of factors—burned land lacking vegetation and sudden, intense rainfall—creates a high likelihood of mudslides, which can lead to hazardous conditions in affected areas.

While soil composition, earthquake activity, and burn scars can influence landslide risks, they do not directly correlate as strongly with the immediate aftermath of a wildfire in the same way that heavy rainfall does. Soil composition can affect erosion rates, but without rainfall, it wouldn't be the direct trigger of a mudslide. Similarly, earthquake activity can lead to landslides but is not a common factor connected specifically with post-wildfire scenarios. Burn scars, referring to the areas where vegetation has been lost due to fire, can indeed increase vulnerability, but heavy rainfall is the primary mechanism that activates the risk of mudslides in these scenarios.