Card a is supported.
The MSI b660m is equipped with titanium inductors and 60 current DrMOS, has a full-size PCIe slot and 2 SSD interfaces supporting PCIe technology, and the network is a combination of 2.5Gbps wired network card and Wi-Fi6E wireless network card. What's more, the mortar motherboard also provides a USB interface with a transmission rate of up to 20Gbps.