About design pattern,how to resolve a design question

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C#

patterns

we have 3 Entities，such as Entity1,Entity2,Entity3；And 5 interfaces，such as Handler1,Handler2,Handler3,Handler4,Handler5；And 2 envirenment，such as E1,E2；we need use Handler1,Handler2,Handler3 to handler Entity1，use Handler4 to handler Entity2，use Handler5 to handler Entity3，and in different envirenment(E1/E2)，the 5 interfaces have different implementation。

How to resolve this question?You can descript it by C#,or give a design diagram. Thanks.