Priority of RankUp Gems defaulted by System

I know the game defaults a priority for RankUp Gem (year-of-release specific) we could use on particular Champs. For example, if I have a generic Five Star 3-to-4 RankUp Gem (2017 or older), mutant class 3-to-4 RankUp Gem (no year specific), mutant class 3-to-4 RankUp Gem (2015), which one I could use first if I want to rank up my 5star Colossus to R4?

Thanks!
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