Multi-Variable Function Fun!

Algebra Level 3
 $$f(x,y)$$ $$z$$ $$f(5,3)$$ $$28$$ $$f(12,10)$$ $$222$$ $$f(9,1)$$ $$810$$ $$f(4,2)$$ $$26$$ $$f(8,3)$$ $$511$$ $$f(10,1)$$ $$911$$ $$f(7,3)$$ $$410$$

What is the formula for this function?

A:

B
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D:

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