Which of the following are two exotic fungi that remain uncontrollable today?

The selection of Dutch Elm and Chestnut Blight as the correct answer is based on their significant historical and ecological impact as exotic fungi that have caused devastating effects on native tree populations and continue to pose challenges in control and management today.

Dutch Elm Disease, caused by a fungus introduced from Europe, has led to the widespread decline of American elm trees across North America. Its transmission through bark beetles has made it particularly difficult to control and eradicate.

Similarly, Chestnut Blight, caused by the fungus Cryphonectaria parasitica, was introduced in the early 20th century and almost eradicated the American chestnut tree from the eastern United States. The loss of these species has had lasting negative effects on the forest ecosystem, including changes in species composition and habitat availability for wildlife.

In contrast, the other options include diseases and issues that, while serious, do not share the same level of uncontrollable impact over time or may have developing control measures. For instance, White Nose Syndrome has generated research efforts to manage its impact on bat populations, while Oak Wilt has various management strategies that can help in certain situations. Thus, the historic context of Dutch Elm and Chestnut Blight aligns with the criteria of being uncontrollable exotic fungi today.