Can you help me solve the java problems?

Given the tree below: Which output is the result of traversing the tree in order? D, B, G, E, H, A, C, I, A, B, C, D, E, F, G, H, D, B, G, E, H, C, I, F, A O F, I, C, A, H, E, G, B, D O A, D, B, G, E, H, C, I, F What rotation is required to fix the following tree? 20 10 30 25 34 O Single rotation centered at 20 Single rotation centered at 25. Single rotation centered at 30. Single rotation centered at 30. Then single rotation at 20. Single rotation centered at 30. Then single rotation at 25. Single rotation centered at 25. Then single rotation at 30. Single rotation centered at 25. Then single rotation at 20