VBA commands for multiple cells?

Hello, I'm a complete amateur in VBA so my question may be stupid but I really don't know how to resolve my problem. So, I have an excel table with multiple drop-down lists. However for certain cells, I'd like to have multiple options choice so I've modified to following code to work for me. The problem is that it works only for one cell and I want it to work for multiple cells but not all: For example; I want to have this multiple choice drop down lists in cells D8, D13, D18 and D21. Can you help me with that please )

Here's the code I'm using.

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