Which Slot to use?

B-key interface can support SATA bus standard and PCI-E bus standard, and it may support AHCI protocol or NVMe protocol M-key interface

Ignite extreme performance from Crucial's Gen5 SSD With blistering speeds of up to 14,50012,700MBs sequential readswrites1, the Crucial T705 outpaces,

m2 slot types 2 PCIe SSD to your PCIe-equipped desktop computer to significantly increase speed and performance Supports PCIE

m2 expansion slot M Key Common Usage: PCIex4 and NVMe SSD M Key Interfaces Support: PCIe x4, SATA, and SMBus B+