What PCIe slots are present on the ASUS PRIME B450M-A II, and what are their lane configurations?

The PRIME B450M-A II runs PCIe 3.0 across the board. You get one x16 slot for your graphics card and two x1 slots for expansion — Wi-Fi, sound cards, that sort of thing. No Gen 4, no lane-sharing complexity, just straightforward PCIe 3.0 that works with everything.