Data Validation list combinations and outcomes

[Noobvhacker]

Hi I have 4 lists and I would like to use data validation selecting from these 4 lists to give me one of 4 possible text outputs as below

What is the best way to do this please - do i need to list out all the possible combinations and my desired outcome for each somewhere on the sheet or is there a clever way of doing it?

Any help is much appreciated.