The exhibit displays a single Optical Transponder (OT) card with two line-side ports. This hardware configuration is designed to support an intra-card line protection scheme, commonly referred to as "Y-cable protection". In this scheme, the client signal is internally bridged to both line-side transmitter ports. To make this protection functional, an external 1x2 Optical Protection Switch (OPS) is required. The OPS is placed between the two line ports of the OT and the single line fiber, where it selects the signal from either the working or the protection port for transmission. The diagram shows the prerequisite hardware (the OT with dual line ports) for this type of protection but lacks the switching component, making the statement that an OPS is required the only correct conclusion.

A. OCH (Optical Channel) protection is a path protection mechanism that requires two physically diverse fiber routes between the endpoints, which is not shown in the exhibit.

B. O-SNCP (Optical Sub-Network Connection Protection) is another form of path protection that also mandates two diverse optical paths, which are not present in the diagram.

C. E-SNCP (Electrical SNCP) is a protection mechanism that operates on the electrical client-side signal, not the optical line side as depicted in the diagram's focus.

1. Nokia 1830 PSS Engineering and Planning Guide (Release 11.1), Document ID: 3KC-13891-AAAA-TCZZA, Chapter 4: "Protection and restoration", Section: "1+1 OTM-internal line-side protection". This section explicitly describes the "Y-cable" protection scheme, stating: "1+1 OTM-internal line-side protection uses a single OTM with two line ports and an external 1x2 optical switch... The OTM internally bridges the signal from the client port to the two line ports." This confirms that an external switch (OPS) is a mandatory component for this configuration to provide protection.

2. Nokia 1830 PSS Optical Layer Guide (Release 11.1), Document ID: 3KC-13893-AAAA-TCZZA, Chapter 3: "Optical protection switching". This chapter details the functionality of OPS cards (like the OPSB) and their application in various protection schemes, including line-side protection for transponders, which aligns with the scenario requiring an OPS for the OT shown. The guide clarifies that OCH and O-SNCP protection schemes involve path-level switching between diverse routes, which is fundamentally different from the hardware setup in the exhibit.