Which two protocols operate at the data link layer of the OSI reference model? (Choose two.)

Spanning Tree Protocol operates entirely at Layer 2, exchanging Bridge Protocol Data Units (BPDUs) as multicast Ethernet frames to elect a root bridge and build a loop-free switched topology with no IP addressing involved.

NetBIOS operates at the Session layer (Layer 5) of the OSI model, providing session establishment and name resolution services well above the Data Link layer.

OSPF is a Layer 3 routing protocol that operates at the Network layer, exchanging link-state advertisements encapsulated directly in IP packets.

ICMP operates at Layer 3 (Network layer), encapsulated within IP packets to convey error messages and diagnostic information such as unreachable destinations or echo requests.

LLDP (IEEE 802.1AB) is a Layer 2 neighbor discovery protocol that advertises device identity and capabilities using multicast Ethernet frames, operating independently of any Layer 3 protocol.