An IP packet isencapsulated in……A. Network layer packetB. Datalink FrameC. Physical layer packetD. All of the mentioned

The correct answer is B. Datalink Frame.

Here's the step by step explanation:

1. The Internet Protocol (IP) operates at the Network layer of the OSI (Open Systems Interconnection) model. This layer is responsible for addressing, routing and (in some cases) error reporting and fragmentation and reassembly.

2. When an IP packet is ready to be sent, it needs to be encapsulated into a frame for transmission over the physical medium. This is done at the Data Link layer.

3. The Data Link layer is responsible for providing reliable transit of data across a physical link. It does this by encapsulating the Network layer data (in this case, the IP packet) into a frame.

4. The frame includes not just the data, but also control information, such as error checking and synchronization bits.

5. Therefore, an IP packet is encapsulated in a Data Link Frame for transmission over the network.

Option D "All of the mentioned" is incorrect because the Physical layer does not encapsulate IP packets. The Physical layer is responsible for the transmission and reception of unstructured raw bit stream over a physical medium. It does not encapsulate or organize these bits in any way.