Hume, Kant, Causality, and Induction

Yes, that’s right: „Kant pointed to the necessity of that 3rd element, »relevance« or usefulness. He proclaimed that it is of necessity that we presume causality. And in that regard, he was right. But that doesn’t exactly answer whether causality is true, but merely why we accept it as true.“ - James S Saint. Is causality true? Is an exactly answer possible?