18. In OSI model, when data is sent from device A to device B, the 5th layer to receive data at B is _
a) Application layer
b) Transport layer
c) Link layer
d) Session layer
Explanation: In OSI reference model, the fifth layer is Session layer. Session layer provides the mechanism for opening, closing and managing a session between end-user application processes. In TCP/IP protocol stack, the functions of the session layer are handled by the transport layer itself and thus the session layer is missing from the TCP/IP model.