What does Oak Wilt primarily cause in trees?

Oak Wilt primarily causes leaf wilting from the margin due to a fungal infection that disrupts the tree's vascular system. This disease is caused by the fungus Ceratocystis fagacearum, which invades the xylem tissue and blocks the flow of water and nutrients throughout the tree. As the disease progresses, leaves may turn brown and appear scorched, often starting at the edges and moving inward, resulting in a characteristic marginal wilting. This symptom is a direct response to the impaired vascular function and can lead to the eventual decline of the tree if not managed. The other potential options describe different issues that are not associated with Oak Wilt, illustrating how this specific symptom distinguishes the disease from other tree health problems.