"Ministère" permit B to A (Brussels)

Hey, I was hoping someone might know what this article is talking about

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It says that to change a permit B to permit A, you need to stay 4 out of 10 years in Belgium, and go fill up the paperwork at "Ministère" for the brussels-capital region. Does anyone know exactly which ministry is this article talking about? Also, does anyone have any personal experience on this process? Thanks.