Which of the following can transmit block level storage over Ethernet?

SAS (Serial Attached SCSI) is a point-to-point serial protocol for direct-attached storage, not a protocol for transmitting storage over an Ethernet network.

iSCSI (internet Small Computer System Interface) is a networking standard that allows the use of the SCSI protocol over TCP/IP networks, effectively providing block-level access to storage over Ethernet connections. It enables a host to see remote storage as if it were directly attached.

USB (Universal Serial Bus) is a direct-attachment interface primarily for connecting peripheral devices and does not transmit block-level storage over an Ethernet network.

SATA (Serial ATA) is an internal interface for connecting storage devices directly to a motherboard within a computer and does not transmit over an Ethernet network.