From type A card to B or D for permanent residency
I am working and living in Belgium for 5 years with an A card. Normally I should be able to apply for permanent card, but my local commune told me my A card is valid till end of 2022 (which is total 7 years at 2022), then I can apply for B card. I don;t understand why the card validity date should be a blocking point. if I fulfill all requirements. On the other hand, they said I can apply for D card which would take 5 months.
Is there any difference between B and D? Is it possible to apply for citizenship later with D card and do both B and D card holders have the right to move to any other European country to work?
Unfortunately the commune is not really helping to understand.