Answer the following question given this paragraph: 

Dutch elm trees used to be common, beautiful trees in the United States. Now most of them, like this tree, have been killed by Dutch elm disease. Dutch elm disease is caused by a fungus. This is just one example of how fungi can interact with other species.


Q: Dutch elm trees used to be common, beautiful trees in the united states. now most of them have been killed by what?

 Choices:

- carbon dioxide

- beetles

- cancer

- dutch elm disease

A:
dutch elm disease
