c# - I want to use 2 dropdown list in a way so that second dropdown list show remaining items of the first dropdown list except the selected one -

I want to use 2 dropdown menus in a way that excludes the second dropdown list and the remaining items in the first dropdown list Show one If you have a solution, please send me as soon as possible at rsolanki 2008@gmail.com.

This problem is called "cascading dropdown" ,.