What is the PDU at Layer 4 called A Data B Segment C Packet

What is the PDU at Layer 4 called?

A. Data

B. Segment

C. Packet

D. Frame

E. Bit

Solution

B is correct. The Layer 4 PDU is called a segment.

A, C, D, and E are incorrect. A is incorrect because the data is the PDU for the top three layers. C is incorrect because the packet is the PDU at the Network layer. D is incorrect because the frame is the PDU for the Data Link layer. E is incorrect because the bit is the PDU at the Physical layer.