The most likely issue is transposed TX/RX. Fiber connections require the transmit strand on one side to connect to the receive strand on the other side, and vice versa. If transmit is connected to transmit and receive is connected to receive, the physical termination may be correct, but the link will not come online because the devices cannot properly send and receive optical signals.
The CompTIA Network+ N10-009 objectives include fiber media, transceivers, connectors, cabling issues, and troubleshooting physical connectivity. A visual fault locator can confirm continuity and help identify breaks, bends, or termination problems, but it does not always prove that the transmit and receive strands are correctly crossed between endpoints.
An incorrect SFP could also cause a fiber link failure, but the question emphasizes that only one connection remains offline after most links came online and that the termination was verified. That makes a polarity issue, such as reversed transmit and receive strands, the strongest answer. Incompatible cable is less likely if similar connections are working. CRC errors usually indicate a link is active but experiencing frame errors, not completely offline. Therefore, transposed TX/RX is correct.

Using a /30 subnet mask is the most efficient way to conserve IP space for a point-to-point connection between two routers. A /30 subnet provides four IP addresses, two of which can be assigned to the router interfaces, one for the network address, and one for the broadcast address. This makes it ideal for point-to-point links where only two usable IP addresses are needed.
Reference: CompTIA Network+ study materials and subnetting principles.

This process describesZero-touch provisioning (ZTP), where a device automatically pulls its configuration from a cloud controller or URL once connected to the internet. It's common in SD-WAN and modern network appliances.
* A. SASE(Secure Access Service Edge) refers to cloud-delivered network security, not a provisioning method.
* C. Infrastructure as codeautomates infrastructure deployment using code, but this scenario specifically fits ZTP.
* D. Configuration managementtracks and maintains system configurations but doesn't describe the installation process.
#Reference:
CompTIA Network+ N10-009 Official Objectives: 4.3 - Explain remote access methods and automation.

Cable termination issues (e.g., improper crimping, loose connectors) can cause connectivity failures.

A full-tunnel VPN routes all user traffic, including internet-bound traffic, through the corporate network, ensuring centralized control and security.