A:Answer My Skytech Chronos came with a ASRock B450M/ac mobo:
https://asrock.com/MB/AMD/B450Mac/index.asp
AMD AM4 Socket
Supports DDR4 3200+ (OC)
1 PCIe 3.0 x16, 1 PCIe 2.0 x16
AMD Quad CrossFireX™
Graphics Output: HDMI
7.1 CH HD Audio (Realtek ALC892 Audio Codec), ELNA Audio Caps
4 SATA3, 1 Ultra M.2 (PCIe Gen3 x4)*
6 x USB 3.1 Gen1 (2 Front, 4 Rear)
Realtek Gigabit LAN
ASRock Polychrome SYNC