Which list correctly names the OSI model layers from bottom to top?

• A. Application layer, Presentation layer, Session layer, Transport layer, Network layer, Data Link layer, Physical layer.
• B. Physical, Data Link, Network, Transport, Session, Presentation, Application.
• C. Physical, Network, Data Link, Session, Transport, Presentation, Application.
• D. Data Link, Network, Physical, Transport, Session, Presentation, Application.

Answer: (B)

Think of the OSI model as a stack of seven layers arranged from bottom to top, with data moving from hardware-facing functions up to user-facing services. The bottom-most layer is Physical, followed by Data Link, then Network, then Transport, then Session, then Presentation, and finally Application at the top. This bottom-to-top sequence is the standard order of the OSI model. The other sequences don’t fit because they place layers out of order—for example, starting with top-layer concepts at the bottom, or swapping adjacent layers like Data Link and Network, or putting Physical after Data Link.